The United Auto Workers (UAW), the Service Employees International Union (SEIU), and other groups plan to file an ethics complaint against Mitt Romney for allegedly failing to disclose his profits from the auto bailout, the UAW has told The Huffington Post.

The groups are calling for an investigation by the U.S. Office of Government Ethics to investigate Romney's alleged violation of the Ethics in Government Act, which requires presidential candidates to disclose their personal finances. The ethics complaint comes on the heels of an Oct. 17 article in The Nation, which alleged that Romney has hidden his personal gains of at least $15.3 million from the auto bailout.

"He made his fortune off the misfortune of others," Bob King, president of the UAW, told The Huffington Post on Wednesday. "Why should we have to find out from the media about this?"

The Romney campaign could not be immediately reached for comment.

The allegations are ironic given that Romney has been a staunch critic of the auto bailout. Romney called for the government to let the auto industry go bankrupt in an op-ed in The New York Times in 2008. The Romney campaign also released a misleading ad in October that implies Chrysler has moved production of Jeeps to China following the auto bailout.

Romney and his wife allegedly made millions from the auto bailout through their investments in the hedge fund Elliott Management, which held a stake in the auto bailout recipient Delphi Automotive, according to The Nation. The return on this investment amounted to more than 3,000 percent, according to The Nation.

That said, the magazine didn't say that Romney broke the law. From The Nation:

In their 2011 and 2012 Federal Financial Disclosure filing, Ann Romney’s trust lists “more than $1 million” invested with Elliott. This is the description for all of her big investments—the minimal disclosure required by law.

The UAW is holding a press conference on the planned ethics complaint at 2 p.m. on Thursday in Toledo, Ohio.

CLARIFICATION: Language has been changed to characterize more specifically the claims regarding Jeep made in Romney's ad.

Earlier on HuffPost:

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  • Paul Krugman

    <a href="http://krugman.blogs.nytimes.com/2012/08/10/culture-of-fraud/">The Nobel Prize-winning economist wrote</a> in a New York Times blog post in August: "Romney’s tax plan is now a demonstrated fraud — big tax cuts for the rich that he claims would be offset by closing loopholes, but the Tax Policy Center has demonstrated that the arithmetic can’t possibly work."

  • Matt Taibbi

    Matt Taibbi, contributing editor to Rolling Stone, <a href="http://www.rollingstone.com/politics/blogs/taibblog/the-vice-presidential-debate-joe-biden-was-right-to-laugh-20121012">wrote in a recent blog post </a>: "If you're going to offer an across-the-board 20 percent tax cut without explaining how it's getting paid for, hell, why stop there? Why not just offer everyone over 18 a 1965 Mustang? Why not promise every child a Zagnut and an Xbox, or compatible mates for every lonely single person?"

  • Larry Summers

    Harvard economist Larry Summers, a former top adviser to President Barack Obama, <a href="http://www.huffingtonpost.com/2012/10/11/larry-summers-romney-tax-plan_n_1958982.html">recently compared Mitt Romney's tax plan</a> to a hamburger and ice cream diet. He said: "It’s easy to say that 'My plan is to eat ice cream sundaes and chocolate cake and hamburgers as much as I want, my plan is to lose 60 pounds, and my plan is to avoid painful exercise, and those are all my objectives and I'm committed to every one of them.'"

  • The Tax Policy Center

    <a href="http://www.taxpolicycenter.org/publications/url.cfm?ID=1001628">The Tax Policy Center</a>, a nonpartisan, nonprofit think tank, <a href="http://www.huffingtonpost.com/2012/09/11/romney-tax-plan-middle-class_n_1874113.html">recently concluded</a> that Mitt Romney's tax plan is mathematically impossible without raising taxes on the middle class.

  • Josh Barro

    <a href="http://www.bloomberg.com/news/2012-10-12/the-final-word-on-mitt-romney-s-tax-plan.html">Bloomberg View columnist Josh Barro wrote</a> in a recent column that the six studies that the Romney campaign uses to claim the candidate's tax plan is mathematically possible "individually and collectively...fail the task."

  • Mark Zandi

    <a href="http://thinkprogress.org/economy/2012/10/12/1004921/zandi-romney-tax-plan/">Mark Zandi</a>, chief economist at Moody's Analytics, recently said on CNN that when it comes to Romney's tax plan, "the arithmetic doesn't work as it is right now."

  • Ezra Klein

    <a href="http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/08/04/romney-tax-plan-on-table-debt-collapses-table/">Washington Post columnist Ezra Klein wrote in August</a> that "the Tax Policy Center’s analysis has removed all doubt" that Romney's tax plan is mathematically impossible.

  • David Frum

    <a href="http://www.thedailybeast.com/articles/2012/10/11/vice-presidential-debate-live-blog.html">David Frum</a>, contributing editor at Newsweek and The Daily Beast, recently wrote: "Romney's tax cut plan doesn't work. I'm a Republican, I support Romney, etc. But you can't cut that much in such a stagnant economy and expect to break even. Even with a deductions cap, it just won't happen."

  • Catherine Rampell

    Catherine Rampell, economics reporter at The New York Times, wrote of the <a href="http://economix.blogs.nytimes.com/2012/10/01/the-math-on-the-romney-ryan-tax-plan/">the Romney campaign's tax promises</a> in a recent blog post: "Not <em>all</em> of those principles can coexist so long as basic arithmetic survives."