MADISON, Wis. (AP) — Authorities say an estimated 25,000 people are protesting anti-union legislation at the Wisconsin state Capitol, and nine demonstrators have been arrested.

On the third day of protests, the Statehouse was completely jammed with protesters opposed to a bill that would strip public employees of their collective bargaining rights. The crowd filled the building’s hallways, sat cross-legged across the floor and chanted slogans.

For the moment, a group of Democratic senators have blocked the bill by refusing to attend a midday vote and leaving the Capitol. The sergeant at arms was looking for them.

One member of the group told The Associated Press that they had all left Wisconsin in an effort to force Republicans to negotiate.

Republicans hold a 19-14 majority, but they need at least one Democrat to be present before voting.

Copyright 2011 The Associated Press.