In the event of a strike, which would become legal as of Jan. 3, 2024 under the Canadian Labour Code, it should be anticipated that all flights will be canceled, the union said in a statement.

Pilots and other workers at carriers such as Southwest Airlines and Delta Air Lines have pushed for better pay and working conditions while negotiating new contracts with company managements at a time when public support for unions is still on the rise.

The strike mandate comes after 33 negotiation sessions and reflects the flight attendants' exceptionally high level of dissatisfaction with their working conditions, particularly with wages and purchasing power, according to the statement.

"More than 50% of them (the members) have been forced to take on a second or even a third job to make ends meet, and their starting salary is only C$26,577 per year," said Dominic Levasseur, president of the Air Transat Component of CUPE.

The collective agreement for 2,100 flight attendants based at airports in Montreal and Toronto expired on Oct. 31, 2022, CUPE said.

The move mimics recent labour unrest by unions at various other industries such as casinos, logistics and automotives.

Canada-listed tour operator Transat AT Inc offers air travel under the Air Transat brand.

Transat was not immediately available for comment.

As of July 31, 2023, Air Transat's permanent fleet consisted of 13 Airbus A330s, 14 Airbus A321LRs and eight Airbus A321ceos.

(Reporting by Ananta Agarwal in Bengaluru; additional reporting by Priyamvada C, Editing by Shilpi Majumdar)