Talks between WestJet and the pilots' union continue amid the countdown toward a Friday strike deadline, with the airline saying it has started to cancel flights ahead of the anticipated work stoppage.

Some 1,800 pilots at the carrier and its Swoop subsidiary are poised to walk off the job as of 3 a.m. eastern daylight time after the Air Line Pilots Association issued a strike notice Monday.

The federal labour minister and the government's head mediator as well as WestJet's CEO and the pilots' union leaders have all descended on a hotel near Toronto's Pearson airport to work toward a deal.

WestJet issued a statement early Thursday saying it has begun cancelling flights in preparation for the job action. 

The statement reads that the WestJet Group is parking the majority of its 737 and 787 fleet in a "measured, phased and safe approach," given that a tentative agreement has not yet been reached. The airline says WestJet Encore, WestJet Link as well as limited 737 flights will continue to operate during this time. 

WestJet chief executive Alexis von Hoensbroech says the union's demands are extreme, while the travel plans of thousands of Canadians hang in limbo ahead of the May long weekend.

Bernard Lewall, who heads the union's WestJet contingent, says the workers' issues revolve around pay, job security and scheduling, with pilots earning roughly half of what some of their U.S. counterparts make.

With more than 4,000 flights scheduled over the next seven days, WestJet carries 28 per cent of Canada's domestic market, while Air Canada runs 47 per cent, according to flight data firm Cirium.

The airline is advising travellers to check the status of their flight before leaving for the airport, and to visit WestJet's Guest Updates page or Swoop's information hub for more information regarding flight status and travel changes.