The Patrick administration is weighing whether to require contractors bidding on certain federally funded stimulus projects to enter into deals with local unions.

The use of "project labor agreements" would mandate contractors sign collective bargaining agreements for specific projects. In return, unions would agree not to strike.

Labor leaders are pushing the administration to require the deals, especially for big ticket stimulus-funded projects. But nonunion contractors say the agreements stifle competition and drive up construction costs.

The agreements have been used on two of the state’s biggest undertakings: the Big Dig and the cleanup of Boston Harbor, including construction of the Deer Island waste treatment plant. (AP)