WestJet is facing more turbulence with its workforce, just weeks after a potential pilot's strike was averted — but this time it involves flight attendants.

The Canadian Union of Public Employees (CUPE) has filed a complaint with federal regulators, claiming that both WestJet and the Calgary Airport Authority are engaging in unfair labour practices.

They claim the airport, at WestJet's request, is blocking union organizers from talking to flight attendants at airport exits.

Ella Henry is a lawyer for the union. She says flight attendants are in a unique situation because their work locations are always changing.

"When employees are not working, when they're on break, when they're on their way to work, coming back from work, employees have the right to talk about joining a union and to take action to that end," she said.

"The workplace is the natural location for employees to talk to each other about a union, and WestJet flight attendants, and flight attendants generally, have a bit of a unique workplace. They don't all work together with set 9-5 shifts. They don't all work in the same place. In fact, they might be all around the world.

"And so the ability to communicate with flight attendants in person at airports is an integral part of CUPE's organizing drive.

Full-time flight attendants are expected to fly 80 hours a month and pay is based on years of experience. Employees are compensated for how many hours they spend in the air, not the length of their shift. (CBC News)

"And without any legitimate business justification for attempting to limit CUPE's ability to contact flight attendants at the airport, it really is just an attempt to interfere in the rights of flight attendants to form a union. And that's contrary to the Canada Labour Code," she added.

David Fleming, an organizer with CUPE's WestJet flight attendant campaign, said some tactics by the company and airport officials have been perceived as intimidating.

"Saying that you don't want a union is different than engaging in tactics that intimidate workers, or intimidate employees from joining a union," he said.

"In this instance we are claiming that there was at least one communication that threatened to close down the company if workers were to unionize — everyone's going to lose their jobs.

"That crosses the line from communication about joining a union to, it creates a culture of hostility and intimidation around it."

Airport officials wouldn't comment on the complaint, saying they haven't yet received a copy.

WestJet also declined to comment while the matter is before the industrial relations board.