Air Canada pilots voted to give their union a strike mandate as negotiations over a new labor agreement have been stalled for more than a year. Workers could walk off the job as soon as mid-September.

The Air Line Pilots Association, representing Air Canada’s more than 5,400 aviators, is in a federal conciliation process with Air Canada until August 26, which will be followed by a 21-day cooling off period. The workers will be in a legal strike position starting Sept. 17.

The unionized pilots gave the strike authorization Thursday morning with a majority of 98%, with 98% of members participating, ALPA said in a statement.

The union seeks to close the pay gap with large US airlines, which have significantly increased their pilots’ pay lately. Canada’s No. 2 airline, Onex Corp.-owned WestJet Airlines Ltd., agreed to a contract in 2023 that included a 24% compensation bump over four years.

Air Canada pilots are paid less than half of what industry counterparts get, according to the union.

“Management continues to force us closer to a strike position by not listening to our needs at the negotiating table regarding fair compensation, respectable retirement benefits, and quality-of-life improvements,” Charlene Hudy, the ALPA’s local head, said in the statement.