Low-cost Canadian carrier WestJet has once again begun cancelling flights after receiving a second strike notice from workers.

Just over a week ago, on June 19, the airline released a statement saying it had started cancelling and consolidating flights in preparation for possible strike action by WestJet Aircraft Maintenance Engineers and other Tech Ops employees.

After 31 flights were preemptively cancelled, WestJet announced at midnight on June 20 that the labour action had been averted. By that point, thousands of customers had already been impacted.

Late Wednesday night, WestJet said it had initiated more flight cancellations to prepare for the "threat of strike" on Friday.

"This action ensures the airline can safely park its aircraft in a controlled manner while enabling proactive communication and preventing the stranding of WestJet's guests and crew," airline officials said.

Around 3,300 flyers will be affected by 25 cancellations spanning Thursday and Friday (June 27 and 28).

This happened after WestJet presented the Aircraft Mechanics Fraternal Association (AMFA) with a "Canadian industry-leading agreement."

"Just hours into day one of a mutually agreed to four-day bargaining period, the union served a strike notice. This timing could disrupt the travel plans of more than 250,000 guests scheduled to travel over the July long weekend and appears to be an attempt to force an unreasonable contract," WestJet's latest statement reads.

WestJet Airlines President and Group Chief Operating Officer Diederik Pen said that as the July long weekend approaches, this strike notice is "especially devastating."

"As we are forced to make this painful decision, every one of us at WestJet feels the immense weight of the impact this will have on each of our guests and the communities we serve, counting on us to fulfil their travel plans this weekend," he stated.

"We remain at the bargaining table, committed to reaching an agreement; however, we have no choice but to hold strong on a reasonable outcome that protects our future and ability to provide Canadians with critical and affordable air travel. As we initiate flight cancellations across our network, we will continue to manage our operations to the highest degree of safety," Pen concluded.

The airline noted that it's making all efforts to re-accommodate affected guests. In the next 48 hours, it will work on parking aircraft in a "measured, phased, and safe" approach.

If you're flying WestJet, check your flight status here before leaving for the airport, and visit the airline's guest updates page for more information regarding flight changes.