The union representing 4,400 flight attendants at WestJet has issued 72-hour strike notice, setting the stage for a work stoppage that could ground flights in the middle of a busy summer long weekend.

As with last summer's brief strike by Air Canada workers, one issue is payment for work performed while on the ground.

The clock is ticking down toward a strike deadline that could see 4,400 WestJet flight attendants hit the picket line as soon as Sunday.