Police officers were dispatched Thursday to find Wisconsin state lawmakers who had apparently boycotted a vote on a sweeping bill that would strip most government workers of their collective bargaining rights.

The lawmakers, all Democrats in the state Senate, did not show up when they were ordered to attend a midday vote on the legislation.

The proposal has been the focus of intense protests at the Statehouse for three days. As Republicans tried to begin Senate business Thursday, observers in the gallery screamed "Freedom! Democracy! Unions!"

Republicans hold a 19-14 majority, but they need at least one Democrat to be present before taking a vote on the bill.

"Today they checked out, and I'm not sure where they're at," Republican Senate Majority Leader Scott Fitzgerald said. "This is the ultimate shutdown, what we're seeing today."

Democratic Minority Leader Mark Miller released a statement on behalf of all Democrats urging Gov. Scott Walker and Republicans to listen to opponents of the measure and seek a compromise. His statement did not address where Democrats were or when they planned to return.

Bill opponents in the Senate gallery cheered when Senate President Mike Ellis announced that there were not enough senators present to proceed.

The bill came to the Senate after the Legislature's budget committee endorsed it just before midnight Wednesday.

Walker and Republican leaders have said they have the votes to pass the plan.

That didn't stop thousands of protesters from clogging the hallway outside the Senate chamber beating on drums, holding signs deriding Walker and pleading for lawmakers to kill the bill. Protesters also demonstrated outside the homes of some lawmakers.

Hundreds of teachers called in sick, forcing a number of school districts to cancel classes. Madison schools, the state's second-largest district with 24,000 students, closed for a second day as teachers poured into the Capitol.