HALIFAX -- The Nova Scotia Teachers Union called for the postponement of the inaugural meeting of a working-conditions committee Wednesday as the minister of labour rejected a request from the union to appoint a mediator to resolve a labour dispute.

The committee -- made up of representatives from the teachers' union, school boards and the education department -- was set to meet Thursday.

But in a news release Wednesday evening, union president Liette Doucet said since agreeing to participate in the committee, Premier Stephen McNeil has insisted that working conditions will only be discussed through this process and not through bargaining.

"The final straw was (Tuesday) when Education Minister Karen Casey held a news conference about teacher workload issues and did not invite or inform the Nova Scotia Teachers Union," said Doucet, citing the minister's decision to suspend some provincial student assessments -- a move the union called "symbolic" as most provincial assessments for this school year are already complete.

"We will not lead teachers into a process with government that appears intended to provide sound bites and distract from our ongoing labour dispute."

Doucet said the union has lost faith that the government is willing to form a partnership based on mutual respect.

Education and Early Childhood Development Minister Karen Casey said she was disappointed by the union's decision, adding the committee will try to find a way for teachers to participate regardless.

"The union does not want to sit down with the department and representatives from the school boards to discuss working conditions," she said. "If the union will not come to the meeting, we still want to hear from teachers."

"If teachers want to speak directly to government, we are here to listen."

Earlier Wednesday, Minister of Labour and Advanced Education Kelly Regan rejected a request from the union to appoint a mediator, saying she doesn't believe an external mediator could help resolve the dispute.

Regan said she'll continue to monitor the situation and is prepared to revisit the decision if circumstances change.

The teachers have voted overwhelmingly in favour of a strike that could take place as early as Dec. 3.

Union members voted 96 per cent in favour of strike action after voting earlier last month to reject the province's latest contract offer -- the second time this year they turned down a tentative agreement.