THE ESCALATING battle between the Nutter administration and the city's largest union is shaping up to be a lightning rod for public-sector labor interests unhappy with the mayor.

Seeking legal permission to impose contract terms on blue-collar District Council 33, the administration on Tuesday asked the state Supreme Court to fast-track its case. The union struck back Wednesday by blasting Nutter for what it sees as an attempt to erase decades of progress for organized labor.

And the stage is being set for a dramatic legal battle that could change the nature of labor negotiations across the state.

"This is the Scott Walker of the east," union president Pete Matthews said Wednesday, likening Nutter to Wisconsin's Republican governor, who dismantled collective-bargaining rights for state employees. "You have a Democratic mayor that's coming out against unions."

Nutter's spokesman, Mark McDonald, said that the Walker comparison was "grossly inaccurate and unfair, and well-nigh hysterical."

He said that current Pennsylvania law, under which cities cannot impose terms, even during an impasse, shifts power "disproportionately toward unions."

"When a union such as DC 33 decides that it doesn't want to bargain, doesn't want to engage in collective bargaining, they just say, 'No,' and they stop cold the process," he said.

The 11,000 workers of DC 33, part of the American Federation of State, County and Municipal Employees, have been working, without raises, on the terms of a contract that expired in 2009.

Since then, the administration has been pushing for the union to accept a deal that includes less-generous pensions, possible furloughs and work-rule changes on overtime. The workers would also get incremental pay raises and cash infusions to the union's beleaguered health-care fund.

The union has held fast in opposition to those changes, especially furloughs, which it considers a nonstarter. Matthews said that he is willing to negotiate other terms if furloughs are off the table.

Nutter, however, contends that further negotiations will be fruitless and wants the Supreme Court to intervene by allowing the city to impose its plan. If he wins, cities across the state may also gain that power in an impasse.