Morry Gash, Associated Press
Protesters yell outside Wisconsin Gov. Scott Walker offivce after a ceremonial bill signing ceremony Friday, March 11, 2011, in Madison, Wis.

MADISON, Wisconsin — Wisconsin Gov. Scott Walker has signed a contentious bill restricting bargaining rights for public employee unions into law, sparking new protests by labor supporters in Madison

Tens of thousands of protesters are expected to turn up for another day of demonstrations at the state Capitol. Clumps of protesters are already walking around the building, shouting "recall Walker."

The bill Walker pushed strips public employees of most of their collective bargaining rights. Tens of thousands of people have been demonstrating against it for more than three weeks, and Senate Democrats fled the state to try to prevent its passage.

But the Republican-controlled Legislature passed the bill this week and Walker signed it into law Friday.

The Senate Democrats are expected to return to Madison on Saturday.