Comcast's plan to buy Time Warner Cable has plenty of detractors, and now it's affecting the hosts at MSNBC.

Writers and producers with the Writers Guild of America-East at Peacock Productions -- which is owned by NBC Universal -- are petitioning Rachel Maddow, Lawrence O’Donnell, Al Sharpton, Ed Schultz and Chris Hayes to speak out against the impending merger. In December, workers accused NBC Universal and Comcast, its parent company, of union busting. The Wrap reported Thursday that they are now concerned that Comcast's deal with Time Warner Cable could lead to even more anti-union behavior.

Both the group and the AFL-CIO have urged MSNBC hosts to speak out against NBC Universal's alleged tactics before. Their latest letter repeats their requests for MSNBC hosts to support workers' attempts to unionize. None of the five hosts have addressed the issue on air, though Chris Hayes met with a group of workers and Ed Schultz defended himself against backlash over his response to a journalist seeking comment on the story.

Meanwhile, NBC Universal has denied the allegations.

(h/t The Wrap)