The carrier, which flies to Heathrow, Gatwick, Edinburgh and Dublin, was due to ground its fleet from 10am UK time today, but action has now been averted. 

The nine-month-old dispute was provisionally settled late on Thursday night. WestJet said: “Both parties now await the ratification vote to be put forward to membership.”

The Calgary-based airline warned there would nevertheless be some disruption and is reported to have cancelled 111 flights.

It said: “The WestJet Group is ramping up its operations as quickly and efficiently as possible, however the full resumption of operations will take time. Guests remain encouraged to continue to check the status of their flights before heading to the airport.”

WestJet group chief executive Alexis von Hoensbroech added: "The WestJet Group is pleased to have reached a tentative agreement that is industry-leading within Canada and recognises the important contributions of our valued pilots by providing meaningful improvements to job security and scope, working conditions and wages.

"We appreciate we were able to arrive at a deal, however, recognise the impact on our guests and we sincerely appreciate their patience during this time.”