A woman works on GM truck engine on the assembly line of the General Motors Flint Assembly Plant January 24, 2011 in Flint, Michigan. - 

President Obama is taking measures to try to close the gender pay gap. On Tuesday, Obama will sign an executive order that bans federal contractors from punishing workers who discuss what they're getting paid.

Although such a measure is already enshrined in law, supporters of the move say many people simply don't know they are legally permitted to talk about wages in the workplace.

Obama will also direct the Labor Department to adopt rules that require those same contractors to provide data on what employees are earning, broken down by race and gender. The orders will only apply to federal contractors, but that's not a small group. 

Samuel Estreicher directs the Center for Labor and Employment Law at the New York University School of Law and jokes - that "federal contractor" is basically a synonym "for multinational corporations, for U.S.-based multinationals."

Companies that have contracts with the federal government include some of the largest corporations in the world, and employ around 26 million people in the U.S.

Follow Noel King at @noeleking