MILWAUKEE (AP) -- Former U.S. Sen. Russ Feingold is back on the campaign trail, this time stumping for Milwaukee Mayor Tom Barrett in the governor-recall race.

Feingold's appearance in Milwaukee on Tuesday was his first with Barrett since the mayor won the Democratic recall primary. Barrett faces Republican Gov. Scott Walker in next month's recall election.

Feingold told reporters he remembers working with Barrett when Feingold was a U.S. senator and Barrett a congressman. Feingold calls Barrett honest, ethical and decent, and says he has the Wisconsin values that Walker lacks.

The Democratic Feingold served three terms before losing a re-election bid in 2010. He says he's planning to make more appearances on Barrett's behalf ahead of the June 5 election.

Walker's campaign spokeswoman didn't immediately respond to an email seeking comment.