Democratic Congressman Rep. Keith Ellison is urging the U.S. Labor Department to step up enforcement against wage theft.

Ellison and two Democratic colleagues wrote to Labor Secretary Thomas Perez this week, asking him to do more to address complaints of companies that hold federal contracts paying workers below the minimum wage, demanding off-the-clock work and denying time-and-a-half pay for overtime.

The lawmakers also asked Perez to make data on wage theft more accessible to federal agencies so they can make better decisions about which companies deserve contracts.

A Senate Health, Education, Labor and Pensions Committee study conducted last year found that companies that hold federal contracts accounted for nearly half of the total fines assessed by the Occupational Safety and Health Administration in 2012.

Ellison has emerged as one of Congress' most vocal advocates for federal workers.

President Obama signed an executive order in February that established a minimum wage of $10.10 per hour for employees on new government contracts after Ellison and other progressive leaders pressed Obama on the issue for most of 2013.

The White House is also developing new rules that would expand the number of employees eligible for overtime pay.

CPC Wage Theft Letter to Perez