Rep. Howard Berman (Calif.) has won the endorsement of a second major labor union in the last month for his primary battle with fellow Democratic Rep. Brad Sherman.

The California arm of the American Federation of State, County and Municipal Employees announced it is backing Berman, who “has been a tireless advocate for the rights of public employees, defending workers’ rights in the courtroom as a labor lawyer and working to achieving collective bargaining rights for thousands of California public employees during his tenure in the state Legislature,” said Barbara Blake, an executive board member.

The endorsement from AFSCME, which has 160,000 members statewide, comes just a few weeks after the Service Employees International Union endorsed Berman over Sherman in the redrawn 30th district. It also came just two days after Berman reported raising eight times as much money as Sherman in the fourth quarter of 2011.

Sherman, who stockpiled money after a decade of noncompetitive races, still had about an $800,000 lead in cash on hand at the beginning of the year and was endorsed last month by the United Steelworkers.