Alberta's public sector unions, which represent tens of thousands of nurses, teachers and government workers, are vowing to fight a new bill delaying wage talks until the end of October.

Bill 9, the Public Sector Arbitration Deferral Act, was introduced Thursday by Finance Minister Travis Toews.

The bill's introduction was witnessed from the public gallery by the leaders of the Alberta Union of Provincial Employees (AUPE), the United Nurses of Alberta (UNA), the Alberta Teachers' Association (ATA) and the Health Sciences Association of Alberta (HSAA), which represent about 180,000 workers.

UNA president Heather Smith led her union through the Alberta government cuts of the 1990s. She says former premier Ralph Klein didn't go as far as the current United Conservative government is attempting to do with Bill 9.

"In the history of our union, it is the biggest betrayal by government we have ever seen in terms of reaching in and using the power of legislation to alter the terms and conditions, and agreed upon, terms of our contract," she said.

Greg Jeffery, president of the ATA, called the bill an affront to his members.

"Six of the last seven years teachers have accepted a zero-per cent increase," he said. "There was hope for this arbitration and to pull that hope away from Alberta's teachers especially at this time of year is tragic."

Toews said the bill doesn't break public sector contracts, but only seeks a delay in the process until the government receives a report on Alberta's finances in mid-August.

But the public sector unions say they suspect this is just the first step in a process that will culminate in legislated wage rollbacks.

"If a government can use the power of the state to take away collective bargaining rights to this degree, they're capable of anything," said AUPE president Guy Smith. "And we're capable of anything to fight back and we will."

Smith said AUPE is still deciding what form that fight will take, but taking the government to court over the bill is on the table.

"The level of anger amongst our members is something I haven't seen in years," he said.

The government has anticipated a court battle. Toews told reporters the government has obtained an opinion on the bill's legality.

"We believe we have a defensible path forward," he said.

The NDP Official Opposition says Toews is breaking the law by not honouring collective agreements. NDP leader Rachel Notley noted that the Supreme Court has upheld the right to strike for public sector workers meaning Alberta union members can legally go on strike.

Contracts for AUPE and the UNA have zero wage increases in the first two years of a three-year contract with a provision for wage talks in the final year.

The Alberta Teachers' Association has a provision for wage talks to go to an arbitrator by the end of September. The HSAA, which represents health care workers like paramedics and lab technologists, also has a wage reopener scheduled for the fall.