Air Canada cancelled at least 30 flights on Friday after what it called an "illegal job action" by some of its pilots, the latest example of tense labour relations at the country's biggest airline.
The carrier, in a heated dispute with two of its key unions, including one representing its 3,000 pilots, said it was exploring its options to deal with the disruption, which came after pilots reportedly called in sick even though they were fit to fly.
It could seek a back-to-work order from an arbitrator, for example, as it did last month during a wildcat strike by ground crew.
Air Canada had cancelled 34 of 690 flights scheduled to depart from Toronto's Pearson Airport, according to the airport's website at mid-day, with a possible snowball effect on flights from other airports.
The pilots union was not available for comment. In a letter earlier this week, it told its pilots that it has not and will not condone illegal actions.
"We are, like you, incredibly frustrated by management's refusal to negotiate with us and by the collusion with the federal government forcing us into a process that we are actively contesting," wrote union chairman Captain Jean-Marc Belanger.
The Canadian parliament passed a law last month that sent separate Air Canada disputes with pilots and machinists to binding arbitration. That prevents the machinists from striking, and the airline from locking out the pilots.
"It is our duty to advise all pilots that ACPA's right to strike and Air Canada's right to lock out its employees are suspended until a new collective agreement takes effect," the pilots union said in its letter.
Noting that it has filed a motion in court to quash the government legislation, the union added that "until the law is struck down, we must all comply with it."
In a letter to the pilots union on Wednesday, Air Canada's director of flying operations said the company would not tolerate pilots abusing the rules about "fitness to fly".
"Be advised that Air Canada reserves its rights to take all appropriate measures to protect itself from the effects of this disruption," wrote Captain Eddy Doyle.
"This could include taking legal action to recover damages or to seek injunctive relief, and may include discipline, up to and including discharge."
RATCHET IT UP
George Smith, a Queen's University labour relations expert and former Air Canada executive said he saw no chance of a positive outcome to the dispute.
"You're going to continue to annoy customers, no doubt there will be a legal response to this, and once again the pilots will be challenged for conducting an illegal strike. The government will say they're not going to tolerate it and ratchet it up again, making it worse, rather than better."
This is the second time in a matter of weeks that the airline has cancelled and delayed flights amid reports of a pilot sick-out. Delays on the previous occasion were also attributed to fog and a fire on a runway at Toronto's Pearson airport.
Air Canada was also hit by a wildcat strike last month, when ground crew workers walked off the job, disrupting dozens of flights.
Canada's Labour Minister Lisa Raitt encouraged the two sides to resolve their disputes and restore passenger confidence.
Air Canada said it would allow customers booked on flights today and tomorrow to book alternate travel without penalty.