The Wisconsin State Assembly approved a bill Thursday that would slash union rights for public workers. The vote comes a day after the state Senate used a legislative maneuver to pass the bill without the 14 Democratic senators who fled the state in an effort to block it.

The bill, proposed by Republican Gov. Scott Walker, is considered the most devastating blow to labor unions in many years and in the last three weeks has drawn thousands of union supporters to the state Capitol in protest. The measure passed the Assembly, 53 to 42. Republicans agreed to two hours of debate before calling a vote.

Before the vote, police briefly locked down the Capitol in Madison Thursday as thousands of protesters swarmed outside and members of the GOP-led State Assembly neared a final vote on a bill that would slash union rights for public workers.

The Assembly session was delayed when some Democratic representatives could not make it into the chamber as at least 100 protesters packed the hallway of the Capitol and pounded on drums.

Police carried out about 50 protesters, according to the Associated Press, and ordered a temporary lockdown while officers did a security review. The doors were opened just before 11:30 a.m., AP said.

Speaking during the session, Rep. David Cullen (D) said that he was turned away by police when he tried to enter the Capitol and "crawled through a window with one of the Republican members on the ground floor."

Earlier Thursday, the Democratic senators who fled Wisconsin last month to try to stall a vote on the measure said they were preparing to return to the state capital and fight back against what one of them called "political thuggery in its worst form."

State Sen. Robert Jauch said the Democrats are discussing ways to overturn the legislation.

After stripping the bill of fiscal measures that require a 20-member quorum for action, Senate Republicans abruptly passed the measure 18-1. Republican Sen. Dale Schultz cast the lone no vote. Analysts say the bill would cripple most of the state's public employee unions.

"They acted more like a third coup than a democratic institution that has long been revered," Jauch said in a telephone interview Thursday.

He said that because the vote was over, there was no reason for the senators to remain out of state. At least two might already be back in Wisconsin, and the rest were preparing to return, Jauch said, adding that he might return on Saturday.

Walker spoke during a Thursday news conference in Milwaukee shortly before the state Assembly was scheduled to take up the measure.