MADISON, Wis. (AP) -- Democratic candidate for governor Tom Barrett has received his first endorsements from unions in the race to recall Republican Gov. Scott Walker.

Barrett announced Thursday that he got the backing of the Amalgamated Transit Union, Operating Engineers Local 317, and the Iron Workers District Council of North Central States. Collectively the three unions represent about 5,000 people.

His rival Kathleen Falk has scored the biggest union endorsements to date, getting backing from the AFL-CIO, the largest statewide public workers union and the union representing teachers.

Both Barrett and Falk say they are committed to restoring collective bargaining rights that were taken away last year by a plan Walker introduced. That largely motivated the recall election.

The Democratic primary is May 8 and the general election is June 5.