The Supreme Court will not hear an appeal from the Alberta Union of Provincial Employees (AUPE) over Bill 9, which delayed wage arbitration between unions and the province in 2019.

In a decision Thursday, Canada's top court dismissed the union's application for appeal, ending a legal battle that began last spring.

As is its custom, the court did not give a reason for dismissing the case.

Bill 9 — the Public Sector Wage Arbitration Deferral Act — was passed by the UCP government in June 2019. It put a halt to wage arbitration talks for three collective agreements affecting 65,000 AUPE members who work for Alberta Health Services or the provincial government.

The workers had previously agreed to a three-year contract with wage freezes in the first two years, with the understanding that wage talks would be re-opened in the final year. The agreement also guaranteed job security until March 30, 2020.

Under the contract, the wage issue was to be decided by an arbitrator by June 30, 2019. The legislation put that process on hold until the end of October.

The then-new United Conservative Party government argued the delay in arbitration was necessary to get a picture of Alberta's finances before committing to any wage increases.

Union officials countered, saying the legislation was unconstitutional and that irreparable harm would be caused to the relationship between union members and their employers if the wage arbitration guaranteed in the collective agreement was not upheld.

In July 2019, the AUPE won an injunction against the bill. Arbitration hearings were set for August.

However, the legislation came back into effect in September after the Court of Appeal of Alberta ruled in favour of the province and overturned an injunction that had blocked the bill.

In a 2-1 decision, the Court of Appeal of Alberta ruled the only harm from Bill 9 was a four-month delay in the start of arbitration. In her dissenting opinion, Justice Marina Paperny wrote that she would have dismissed the appeal.

The AUPE, in turn, sought to appeal the decision to the Supreme Court.

"Bill 9 is a political decision by the UCP government to attack our constitutional rights, our wages, our working conditions and the vital public services Albertans depend on," AUPE president Guy Smith said in a statement following the Alberta appeal court decision.

The AUPE also plans to challenge the constitutionality of Bill 9 with the aim of having it struck down.