Photo: The Canadian Press. All rights reserved.

Dozens of flights at Toronto Pearson International Airport were delayed or cancelled Friday because of a labour dispute at a company that's losing a contract to fuel planes for multiple airlines.

A union spokesman says 30 of 47 workers scheduled for the Friday morning shift called in sick, while others refused to work overtime. He said the dispute could continue all day because more than half of the afternoon shift also called in sick.

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

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

He said employees of Consolidated Aviation Fueling Services will have to apply for the same type of job at another employer at lower wages.

Workers currently earning between $18 and 23 per hour will start at minimum wage up to a high of $14 with no pensions, Trbovich added.

Consolidated Aviation Fueling didn't immediately return calls seeking comment.

The airlines are switching to Service International Group in Toronto as of Oct. 1 and moved to Swissport in Montreal as of July 1.

The Greater Toronto Airport Authority said 36 flights were cancelled as of mid-morning, accounting for about 4.3 per cent of departures. Other flights were delayed.

Some arrivals have also been affected, including two Air Canada flights from Trudeau International Airport even though an airport spokeswoman said there was no job action in Montreal.

Pearson spokeswoman Shabeen Hanifa said passengers should check their flight status online, but wouldn't how many airlines were affected.

The cancellations and delays primarily affected Air Canada, which uses Pearson as its main international hub. Air Transat said none of its flights have been affected. Several WestJet (TSX:WJA) flights were delayed but none was cancelled.

Air Canada spokesman Peter Fitzpatrick said the dispute is between the airlines' current refuelling company and its Toronto workers.

"Delays and cancellations can be expected as a result and passengers should check on the status of their flight before getting to the airport," he said in an email.

Fitzpatrick said a fuel consortium, managed by the FSM Management Group for the airlines, notified Consolidated's parent last fall that it would not renew the agreement that was set to expire March 31. They extended the agreement until the work is taken over by the new fuel providers.