Wisconsin Gov. Scott Walker (R) is trying to "bust" unions with a bill that would curtail certain bargaining rights, Sen. Al Franken (D-Minn.) said Thursday.

"I think the governor is clear that he's trying to union bust," Franken said at a press conference, according to The Minnesota Star-Tribune. "He's gotten the concessions on salaries and pensions that he wants."

It's a rare comment by Franken on a national event. The first-term senator typically concentrates on issues related to his state.

After almost two weeks of increasingly heated protests over a controversial bill by Walker, which would cut back some bargaining rights and benefits for Wisconsin public employee unions, the state's assembly agreed to end debate on Thursday and vote on the bill, which is likely to pass and go to the Wisconsin state Senate. But the bill probably won't get any further unless some of the 14 Democratic state senators who fled the state to block the measure return to vote on it.

Walker has been pushing the Democrats to return. On Thursday he said that their self-imposed exile from the state was a "vacation."

After the press conference Franken also broached a prank phone call by a liberal blogger to Walker.

"I don't believe in punking anybody," Franken said.