Travellers trying to fly out of Toronto Pearson International Airport saw their plans disrupted on Friday, when approximately 100 flights were cancelled or delayed as a result of a labour disruption.

The Greater Toronto Airport Authority says 95 flights have been cancelled as of late Friday afternoon. That accounts for approximately 11.2 per cent of the nearly 850 daily departures at the Toronto airport.

The disruption is a result of a protest by workers who are facing potential job losses in the fall, when a refuelling contract will change hands.

Beginning Oct. 1, a number of airlines are switching their refuelling business to Service International Group in Toronto.

According to a union spokesperson, employees of Consolidated Aviation Fueling Services will be required to apply for a similar position with Service International. The workers, however, will likely be paid less and will not have a pension.

A release by the union says approximately 300 of its members in Toronto and Montreal will lose their jobs by October.

"Basically these guys are all going to lose their jobs Oct. 1, and so I think frustration is they key phrase," Bill Trbovich of the International Association of Machinists and Aerospace Workers told The Canadian Press.

He said workers currently earning between $18 and $23 per hour will likely start at minimum wage, up to a maximum of $14 per hour.

Earlier on Friday, 30 of 47 workers who were scheduled to work the morning shift called in sick, while other refused to work overtime.

Trobich says 20 of 56 workers have showed up for the afternoon shift and there is still another shift remaining to provide fuel for the remaining flights on Friday night.

The union representing the workers says it has encouraged them to return to work.

It's unclear if the job action will continue on Saturday.

"It's one of those cases of they took matters into their own hands," Trbovich said. "We sure as hell don't condone this but the airlines are the one that started this."

He added that bulletins have been sent out explaining to workers that their job action is "unlawful" and there may be consequences if it continues.

The majority of the cancellations and delays have affected Air Canada, which uses the Toronto airport as its main international hub.

"Delays and cancellations can be expected as a result and passengers should check on the status of their flight before getting to the airport," Air Canada spokesperson Peter Fitzpatrick told the Canadian Press in an email.

Air Transat said none of its scheduled flights have been affected, and about a dozen WestJet flights have been cancelled a few delayed.

Travellers are urged to check their flight status before heading to the airport. 

With files from The Canadian Press