The Ontario English Catholic Teachers' Association is filing for conciliation while it continues to bargain with the Ontario government.
The union cited difficulty making progress in negotiations.
"Catholic teachers have been bargaining with representatives from the Government of Ontario and Catholic school boards for almost 18 months," said President Rene Jansen in de Wal. "While the process continues to move forward, with a clear improvement in tone at the table since our overwhelming 97 per cent strike vote, realizing actual progress remains extremely slow.
Talks will continue as the union reaches out to the Ministry of Labour. It will appoint a conciliator.
"Catholic teachers have been beyond patient, especially as other education affiliates reach tentative agreements," continued Jansen in de Wal. "Given these agreements, we are hopeful that with the support and expertise of an appointed conciliator, we can make more significant progress, quicker."
Education Minister Stephen Lecce responded, calling the decision disappointing.
"We stand with parents who want their children to stay in the classroom," said Lecce. "We will work with the conciliator to reach a fair deal that provides stability for families."
The Elementary Teachers Federation of Ontario announced a tentative deal on November 21 but has yet to release a date for the ratification vote to start. The Ontario Secondary School Teachers Federation has had an agreement since August.
Jansen in de Wal assures parents the latest development is not a signal the union will order its members to walk off the job.
"This does not mean the Association will begin a strike or job action," he said. "Filing for conciliation is a crucial tool in the bargaining process, in which parties work with a neutral third party in an attempt to move negotiations forward to reach a central tentative agreement."