The group aiming to form a union among WestJet's pilots has filed for a certification vote.

Earlier today, the WestJet Professional Pilot`s Association filed an application for certification with the Canadian Industrial Relations Board.

One of the requirements to make this application is a demonstration of more than 40 per cent support for WPPA via membership card count. The WPPA said that it comfortably exceeds this threshold.

In a statement on its website, the WPPA said that once the application is approved, the CIRB will conduct and oversee a secure, secret ballot vote of all eligible WestJet pilots to determine support for creating its own in-house, independent and legally recognized Pilot Association.

"This will be the first time in WestJet's 19-plus-year history that our pilots will have an independent third party run a completely confidential vote."

The WPPA has been working since 2013 to organize pilots into a formal bargaining unit. It had been working against a deadline of June 16 for ​something called automatic certification, in which a union can certify if 50 per cent plus one employee signs a union card.

However, that deadline passed and now federally regulated employees, such as those who work in the airlines, can call for a certification vote once 40 per cent of employees have signed a union card.

That vote is thought to add an extra hurdle to the process.

"Once the secret ballot is called, it's a clear signal to management to start campaigning against certifying," said Frances Middleton, a labour lawyer with Jewitt McLuckie. "You'd want to have a nice buffer of employees who signed cards."

Both WestJet's chief executive, Gregg Saretsky and its founder and chairman Clive Beddoe sent company wide emails earlier this month imploring pilots and flight attendants to think hard before signing union cards.

Saretsky's email said that forming a union would not guarantee anything, including current wages and working conditions.

"We are aware of this development," said Brie Ogle, WestJet's spokepeson in an email. "And we await actual service of the application as required by law."