PUBLIC service and teaching unions in the US state of Wisconsin have scored a major legal victory with a ruling that restores collective bargaining rights that they lost under a 2011 state law, which sparked weeks of protests.

That legislation, known as Act 10, effectively ended the ability of most public employees to bargain over wage increases and other issues and forced them to pay more for health insurance and retirement benefits.

Under the ruling by Dane County Circuit Judge Jacob Frost, all public-sector workers who lost their collective bargaining power will have it restored to what was in place before 2011. 

They will be treated the same as members of unions representing police officers, firefighters and other emergency service workers, which were exempted from the law.

Republicans vowed to immediately appeal against the ruling, which is likely to end up before the Wisconsin Supreme Court. 

Former governor Scott Walker, who proposed the law, lambasted the ruling as “brazen political activism.”

But union leaders were overjoyed at the court’s decision, which affects tens of thousands of public-sector staff.

Association of State County and Municipal Employees Local 1215 president Ben Gruber said: “We realise there may still be a fight ahead of us in the courts, but make no mistake, we’re ready to keep fighting until we all have a seat at the table again.”