VANCOUVER -- A potentially costly court ruling that found the British Columbia government violated the rights of its teachers and ordered hundreds of clauses restored to their collective agreement has been put on hold until an appeal is heard.

The ruling Wednesday by the B.C. Appeal Court is the latest volley in a decade-long legal battle between the government and its teachers and yet another wrinkle in contract negotiations already steeped in acrimony.

The provincial government is appealing a ruling released last month by the B.C. Supreme Court, which struck down legislation that removed class size and composition from the teachers' contract. The ruling also concluded the government attempted to provoke a strike and awarded the B.C. Teachers' Federation $2 million.

The province asked the Appeal Court to temporarily stay the ruling, which it argued would create chaos as school boards scrambled to hire teachers and find the money to pay them.

Those consequences could not be reversed if the court ruling is later overturned, the government warned.

In a written decision, Justice David Harris agreed. He found that restoration of the deleted clauses would require substantial changes and it would be impossible to turn back the clock if the government were to win the appeal.

"It is clear, in my view, that the harm suffered in implementing the judgment is irreparable," Harris wrote.

The case dates back to 2002, when the Liberal government used legislation to remove numerous contract clauses related to the size and composition of classrooms.

The B.C. Supreme Court struck down the legislation as unconstitutional in 2011. A year later, the government passed a similar law, which retroactively removed classroom conditions from the contract but allowed the issues to be discussed in future negotiations.

That revised law was declared unconstitutional last month, prompting the province to launch the current appeal.

Education Minister Peter Fassbender has suggested the ruling could cost as much as $1 billion. However, the teachers' union insists that figure is significantly inflated and a government lawyer acknowledged in court last week that the precise cost is uncertain.

The union said delaying the ruling would hurt its bargaining position, because the deleted clauses would not be considered part of the current contract.

The judge disagreed.

"I am not persuaded that an interim stay pending appeal will, as argued, materially fetter the current bargaining process," wrote Harris.

"The parties are sophisticated. They fully understand that a stay indicates nothing about which party's legal position will prove to be correct on appeal."

The education minister welcomed the ruling.

"We now are going to allow the court process to take its natural course, and what I am again focusing on, we need to go back to the bargaining table," Fassbender told reporters in Victoria.

Earlier this month, Fassbender criticized the ruling, arguing it removed the government's ability to set education policy and put the union's interest ahead of students.

The president of the teachers' union, Jim Iker, said he hopes the appeal will be expedited to settle the issue. A hearing is expected as early as May or June.

"We hope that (the appeal) hearing happens sooner rather than later so we can have certainty going into the next school year," Iker said Wednesday.

"In the meantime, it's important that we keep going at the bargaining table."

The union has already announced a strike vote, planned for next month.

Iker said the union's initial proposal to government negotiators in the current round of bargaining already included the deleted clauses as a starting point.

The lower court ruling also permitted the union to distribute its written closing submissions, which contained references to sealed cabinet documents.

The Appeal Court has stayed that aspect of the ruling, as well, until the appeal is finished.