Calls for a general strike are growing among union members and supporters as the state Legislature advanced a law stripping public sector unions of almost all bargaining rights, but it remains unclear whether strikes or pickets will appear soon.

Union leaders say the Republicans' fast-track passage of the bill has fueled strike talk, but for now most are urging legal measures such as recall of Republican legislators as a way to repeal the law.

"A general strike would be playing the trump card, and you don't play the trump right away, you build up to that," said Jim Cavanaugh, president of the 45,000-member South Central Federal of Labor in Madison.

The federation endorsed a general strike on Feb. 21 and on Thursday began distributing educational materials on how such a strike can be accomplished.

"To do it right, there's a lot of preparation," Cavanaugh said. "If you do it lightly you're going to end up with more problems. You're exposing people to job loss and other repercussions if appropriate steps aren't taken."

Among the materials are two pages of logistical issues that were dealt with in series of general strikes in Ontario in the late 1990s, and a memorandum on how to strike and picket without risking discipline, fines or jail.