WASHINGTON -- Thousands of labor supporters turned out to Michigan's Capitol on Tuesday, as the legislature reconvened to vote on "right to work" legislation. By mid-morning, authorities estimated that there were approximately 10,000 people gathered outside the building in Lansing, Mich., with another 2,500 inside.

But despite the show of solidarity, the writing appeared to be on the wall for unions. The legislature's top priority for the day was to pass the contentious bill, and labor leaders acknowledged that they expected Gov. Rick Snyder (R) to sign it into law, making Michigan the 24th state with such a measure. Around noon, the House approved the bill.

Republicans attempted to make the bill repeal-proof, attaching a $1 million appropriation on the measure for enforcing right to work. According to Michigan law, spending bills can't be put on the ballot for the public to vote on.

But labor leaders haven't given up. They've been busily searching for other ways to repeal it, either through the ballot box or within the legislature. Some of the options being discussed depend on the goodwill of the governor or Republicans in the legislature, making those paths unlikely. Michigan House Speaker Jase Bolger's (R-Marshall) office did not return a request for comment.

In the hours before the legislature reconvened, interest in the labor community began swirling around a possible "citizens initiative" to force the right-to-work measure onto the ballot.

"Whether it's the still-available ballot initiative option, or the 2014 elections themselves, Governor Snyder should rest assured that the voices of Michiganders will be heard," said Eddie Vale, spokesman for the labor PAC Workers’ Voice, who was heavily involved in the labor fights in Ohio and Wisconsin. Vale stressed that it's still too early to tell exactly which route will be the best to seek repeal of right to work, should Snyder sign it into law.

Right-to-work laws forbid contracts between companies and unions that require all workers to pay the union for bargaining on their behalf. Although business groups and conservatives cast the issue in terms of workplace freedom, unions note that the laws allow workers to opt out of supporting the union although they reap the benefits of the collective bargaining. Because the laws tend to weaken unions generally, unions, as well as President Obama, call the legislation "right to work for less."

A look at some of labor's options:

  1. Line-Item Veto: Snyder could sign right to work into law but still throw labor a bone by using his line-item veto power to strike the $1 million appropriation in the bill, according to Rep. Gary Peters (D-Mich.). That way, the law would be eligible to go on the ballot, putting the ultimate decision on right to work to the people.
  2. Citizens Initiative: This route may be labor's best route to the ballot box. According to an analysis by the Citizens Research Council of Michigan and first reported by NBC's Mike O'Brien, labor supporters could need to gather a high number of signatories to force a vote to repeal the law, similar to what was done in Ohio with the repeal of an anti-collective bargaining law. This route does not require the removal of the appropriations in the legislation.
  3. Repeal Legislation: Republicans will retain a majority in the legislature in the next session, but their ranks will be reduced after they lost a handful of seats in the 2012 elections. Not all Republicans were on board with right to work in this session, so Democrats could attempt to gain some GOP support for a bill to repeal the law.
  4. Recalling GOP Lawmakers: Labor leaders have raised the suggestion of trying to recall Republicans who back right to work, similar to what was attempted in Wisconsin after Gov. Scott Walker (R) and the GOP-controlled legislature pushed though a bill that stripped most public workers of their collective bargaining rights.
  5. 2014 Elections: Snyder is up for reelection in 2014. There's little doubt that unions will put their muscle into getting him out of office.
  6. Lawsuits: A union activist has already filed a lawsuit in an attempt to slow down the right-to-work legislation, "alleging violations of the Open Meetings Act after the Michigan State Police barred the doors to the Capitol," according to the Detroit Free Press. The Associated Press recently reported that opponents are considering other possible lawsuits.

While the law would be implemented before some of these options -- such as waiting for the 2014 elections -- could go into effect, it would apply only to new contracts, not existing ones. For example, the United Auto Workers just signed a new contract, which means if the law were repealed in 2013 or 2014, it wouldn't affect on those workers, or any others in a similar position.

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  • Protesters Hold Signs Outside Of Michigan Capitol

    LANSING, MI, - DECEMBER 11: Union members from around the country rally at the Michigan State Capitol to protest a vote on Right-to-Work legislation December 11, 2012 in Lansing, Michigan. Republicans control the Michigan House of Representatives, and Michigan Gov. Rick Snyder has said he will sign the bill if it is passed. The new law would make requiring financial support of a union as a condition of employment illegal. (Photo by Bill Pugliano/Getty Images)

  • Protesters Flood Lansing

    LANSING, MI, - DECEMBER 11: Union members from around the country rally at the Michigan State Capitol to protest a vote on Right-to-Work legislation December 11, 2012 in Lansing, Michigan. Republicans control the Michigan House of Representatives, and Michigan Gov. Rick Snyder has said he will sign the bill if it is passed. The new law would make requiring financial support of a union as a condition of employment illegal. (Photo by Bill Pugliano/Getty Images)

  • Protesters Flood The Capitol

    Protesters gather for a rally at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Protesters gather for a rally at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • A protester walks past Michigan State Police at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Sheet metal workers from Toledo escort an inflatable rat during a march to the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. (AP Photo/Carlos Osorio)

  • Thousands of supporters rally at the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. (AP Photo/Carlos Osorio)

  • Union members Brian Brissette, of Auburn, Mich., from left, Tom Gazley, of Romeo, Mich., and Eric Kozlow, of Warren, Mich., watch the Michigan House of Representatives vote on a television in the at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Michigan State Police surround a man who was allegedly knocked off his segway scooter by a sheriff deputy on horseback during a rally on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. (AP Photo/Carlos Osorio)

  • Protesters gather for a rally in the rotunda at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Thousands of supporter march to the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. (AP Photo/Carlos Osorio)

  • Michigan State Police stand guard at an entrance to the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. (AP Photo/Carlos Osorio)

  • Protesters gather for a rally in the rotunda at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Protesters gather for a rally outside the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • RIGHT TO WORK

    Map locating all U.S. states with right-to-work laws.

  • Tuesday Protests

    People begin gathering outside on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012 to protest right-to-work legislation that was passed by the state legislature last week. Michigan will become the 24th right-to-work state, banning requirements that nonunion employees pay unions for negotiating contracts and other services. (AP Photo/Carlos Osorio)

  • Right to Work Michigan

    A protester holds a sign addressed to Michigan Governor Rick Snyder, who refers to himself as "one tough nerd."

  • State Police Brace For Protesters

    Michigan State Police cruisers line the pedestrian walkway west of the state Capitol in Lansing, Mich., Monday, Dec. 10, 2012. Lansing authorities were bracing for an onslaught of protesters Tuesday. They increased police presence and planned road closings and parking restrictions around the Capitol for the planned protests against the Michigan legislature's right-to-work proposals which passed last week. (AP Photo/Carlos Osorio)

  • Right to Work Protesters

    United Auto Workers protest right to work.

  • Tuesday Protesters

    Thousands of protesters gather for a rally on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. Michigan will become the 24th right-to-work state, banning requirements that nonunion employees pay unions for negotiating contracts and other services. (AP Photo/Carlos Osorio)

  • Michigan Nurses

    About a dozen members of the Michigan Nurses Association stand on the state Capitol steps in Lansing, Mich., Monday, Dec. 10, 2012, protesting right-to-work legislation. Organizers say the gathering was meant to symbolize the silencing of unions that nurses say will happen should the legislation become law.(AP Photo/Carlos Osorio)

  • Silenced

    Debbie Nault from the Michigan Nurses Association stands with other members of the association on the state Capitol steps in Lansing, Mich., Monday, Dec. 10, 2012, protesting right-to-work legislation. Organizers say the gathering was meant to symbolize the silencing of unions that nurses say will happen should the legislation become law.(AP Photo/Carlos Osorio)

  • Longtime Nurse Protests

    Linda Erspamer a veteran nurse of more than 30 years at Sparrow Hospital in Lansing, stands with other dozen members of the Michigan Nurses Association on the state Capitol steps in Lansing, Mich., Monday, Dec. 10, 2012, protesting right-to-work legislation. Organizers say the gathering was meant to symbolize the silencing of unions that nurses say will happen should the legislation become law.(AP Photo/Carlos Osorio)

  • Thousands Gather

    Thousands of protesters gather for a rally on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. Michigan will become the 24th right-to-work state, banning requirements that nonunion employees pay unions for negotiating contracts and other services. (AP Photo/Carlos Osorio)

  • Blocking RTW Banner

    Protesters stand and block a right-to-work banner on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation that was passed by the state legislature last week. Michigan will become the 24th right-to-work state, banning requirements that nonunion employees pay unions for negotiating contracts and other services. (AP Photo/Carlos Osorio)

  • Holding The Flag

    A protester holds an American flag at a rally on the State Capitol grounds in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Protesters In The Capitol

    Protesters gather for a rally in the State Capitol rotunda in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Capitol Filled

    Union workers fill the entire of the Capitol rotunda in Lansing, Mich., Thursday, Dec. 6, 2012. Hundreds of chanting and cheering protesters streamed back into the Michigan Capitol after receiving a court order saying that the building must reopen. The pro-union crowd walked in as lawmakers were debating right-to-work legislation limiting union powers. The Republican-led House subsequently passed the bill with no Democratic support.

  • Led Away

    Protesters are led out of the State Capitol Building in handcuffs after demonstrating against right-to-work legislation inside the Capitol in downtown Lansing, Mich. Thursday, Dec. 6, 2012. Eight people were arrested for resisting and obstructing when they tried to push past two troopers guarding the Senate door, state police Inspector Gene Adamczyk said. The Capitol was temporarily closed because of safety concerns.

  • Handcuffed

    Protesters are led out of the State Capitol Building in handcuffs after demonstrating against right-to-work legislation inside the Capitol in downtown Lansing, Mich. Thursday, Dec. 6, 2012. Eight people were arrested for resisting and obstructing when they tried to push past two troopers guarding the Senate door, state police Inspector Gene Adamczyk said. The Capitol was temporarily closed because of safety concerns.

  • Blocked

    State Police block protesters outside the Senate chamber at the State Capitol Building in downtown Lansing, Mich. Thursday, Dec. 6, 2012. Eight people were arrested for resisting and obstructing when they tried to push past two troopers guarding the Senate door, state police Inspector Gene Adamczyk said. The Capitol was temporarily closed because of safety concerns.

  • Thumbs Down

    David Dudenhoefer, left, a right to work supporter, receives a thumbs down sign from a union worker during a rally in Lansing, Mich., Thursday, Dec. 6, 2012. Tensions rose at the Capitol late Wednesday afternoon when hundreds of union members packed into the rotunda area, blowing whistles and shouting slogans such as "Union buster" and "Right to work has got to go." Senate Republicans introduced right-to-work legislation in the waning days of the legislative session as outnumbered Democrats pledged to resist the proposal and say rushing it through would poison the state's political atmosphere.

  • Fed

    Protesters eat pizza outside the Senate chamber at the State Capitol Building in downtown Lansing, Mich. Thursday, Dec. 6, 2012. So-called right-to-work measures generally prohibit requiring unions from collecting fees from nonunion employees, which opponents say drains unions of money and weakens their ability to bargain for good wages and benefits. Supporters insist it would boost the economy and job creation.

  • Union Workers Rally

    Union workers rally outside the Capitol in Lansing, Mich., Thursday, Dec. 6, 2012 as Senate Republicans introduced right-to-work legislation in the waning days of the legislative session. The outnumbered Democrats pledged to resist the proposal and said rushing it through the legislative system would poison the state's political atmosphere.

  • UAW President Bob King Waits

    United Auto Workers President Bob King waits outside the Capitol in Lansing, Mich., Thursday, Dec. 6, 2012 as Senate Republicans introduced right-to-work legislation in the waning days of the legislative session. The outnumbered Democrats pledged to resist the proposal and said rushing it through the legislative system would poison the state's political atmosphere.

  • Rally Day

    A union steel worker holds up a sign during a rally outside the Capitol in Lansing, Mich., Thursday, Dec. 6, 2012 as Senate Republicans introduced right-to-work legislation in the waning days of the legislative session. The outnumbered Democrats pledged to resist the proposal and said rushing it through the legislative system would poison the state's political atmosphere.

  • Sheet Metal Workers Bring GOP Rats to Protest

    <a href="http://www.huffingtonpost.com/social/Paul_Pimentel"><img style="float:left;padding-right:6px !important;" src="http://graph.facebook.com/1419408869/picture?type=square" /></a><a href="http://www.huffingtonpost.com/social/Paul_Pimentel">Paul Pimentel</a>:<br />Sheet Metal Workers' Local 292 Detroit on RTW Protest 12/11/2012 Lansing, MI show our support Bob Donaldson Business Manager and Journeyman Earl Gray

  • The Welcoming Committee

    <a href="http://www.huffingtonpost.com/social/Concernedwm"><img style="float:left;padding-right:6px !important;" src="http://s.huffpost.com/images/profile/user_placeholder.gif" /></a><a href="http://www.huffingtonpost.com/social/Concernedwm">Concernedwm</a>:<br />Gov. Snyder took theses folks away from protecting the public to intimidate and inhibit the voice of the people. G. Hines

  • Protester Paula Merwin, of Leslie, Mich., stands with an American flag outside the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Protester Blake Nance, of Detroit, stands by a line of Michigan State Police guarding the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • A man covers his face after getting pepper sprayed during a protest outside the George W. Romney Office Building in Lansing, Mich., Tuesday, Dec. 11, 2012. Thousands of protesters rallied outside the state Capitol as lawmakers pushed final versions of right-to-work legislation. The GOP majority has used its superior numbers and backing from Gov. Rick Snyder to speed the legislation through the House and Senate last week, brushing aside denunciations and walkouts by helpless Democrats and cries of outrage from union activists who swarmed the state Capitol hallways and grounds. (AP Photo/Carlos Osorio)

  • United we Bargain Divided We Beg!

    <a href="http://www.huffingtonpost.com/social/Ryan_Van_Note"><img style="float:left;padding-right:6px !important;" src="http://graph.facebook.com/1640357026/picture?type=square" /></a><a href="http://www.huffingtonpost.com/social/Ryan_Van_Note">Ryan Van Note</a>:<br />Ryan VanNote protesting Right to work in Lansing, MI 12/11/12.

  • A protester rallies in front of Michigan State Police at the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Michigan State Police push the crowd back outside the George W. Romney Office Building in Lansing, Mich., Tuesday, Dec. 11, 2012. Thousands of protesters rallied outside the state Capitol as lawmakers pushed final versions of right-to-work legislation. The GOP majority has used its superior numbers and backing from Gov. Rick Snyder to speed the legislation through the House and Senate last week, brushing aside denunciations and walkouts by helpless Democrats and cries of outrage from union activists who swarmed the state Capitol hallways and grounds. (AP Photo/Carlos Osorio)

  • Michigan State Police surround the George W. Romney State Office Building as thousands of protesters rally outside the state Capitol as lawmakers push final versions of right-to-work legislation in Lansing, Mich., Tuesday, Dec. 11, 2012. The GOP majority has used its superior numbers and backing from Gov. Rick Snyder to speed the legislation through the House and Senate last week, brushing aside denunciations and walkouts by helpless Democrats and cries of outrage from union activists who swarmed the state Capitol hallways and grounds. (AP Photo/Carlos Osorio)

  • Protesters sit during a rally at the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Michigan State Police push protesters away from the entrance of the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Rev. Jesse Jackson, left, and Lansing Mayor Virg Bernero, right, try to enter past Michigan State Police at the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Michigan State Police carry a protester from a rally at the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)

  • Drew Dobson, of Coleman, Mich., protests at a rally at the State Capitol in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)p

  • Protesters sit during a rally outside the doors of the George W. Romney State Building, where Gov. Snyder has an office in Lansing, Mich., Tuesday, Dec. 11, 2012. The crowd is protesting right-to-work legislation passed last week. Michigan could become the 24th state with a right-to-work law next week. Rules required a five-day wait before the House and Senate vote on each other's bills; lawmakers are scheduled to reconvene Tuesday and Gov. Snyder has pledged to sign the bills into law. (AP Photo/Paul Sancya)