Mary Beth Maxwell, the executive director of American Rights at Work, is leaving the organized labor coalition for the U.S. Department of Labor, the group announced on Friday.

Maxwell will be a senior adviser under Secretary of Labor Hilda Solis, a former Democratic lawmaker from California, focusing on “restoring labor standards, improving workplace safety, enhancing work and family balance, protecting retirement security, and helping protect middle- and working-class incomes,— according to a statement out Friday.

American Rights at Work will now be led by current deputy director Kimberly Freeman and former House Minority Whip David Bonior (D-Mich.), the group’s chairman. Bonior and the organization have been ardent supporters of “card check— legislation, a bill that would make it easier for employees to form unions but one that faces stiff opposition from the U.S. Chamber of Commerce and other business leaders.

In a statement today, Bonior said that the card check bill “is as strong as ever— and suggested that Maxwell’s appointment will bolster their efforts in passing the controversial bill. The legislation faces uncertain prospects after Sen. Arlen Specter (R-Pa.) — who likely would cast the bill’s deciding vote — recently said in a floor speech that he does not support it.