An illegal work stoppage by Air Canada baggage handlers and ground staff disrupted dozens of flight schedules across the country and threw Canada's busiest airport into confusion and chaos.

By the time the workers ended the 12-hour walkout on Friday morning, the job action had caused at least 84 cancellations at Toronto's Pearson International Airport and another 80 delays.

Passengers spent much of the day trying to find their baggage and a way to reach their destinations, and the unrest quickly spread to airports in Quebec City, Montreal and Vancouver.

The carrier issued a statement apologizing to affected passengers and urging those with travel plans to check the status of their flights online, rather than calling. Passengers whose flights have been cancelled will be permitted to rebook without penalty.

The airline said late in the afternoon that "delays and cancellations of Air Canada-operated flights primarily to Canadian and U.S. destinations are expected for the remainder of the day." Some passengers would not be able to fly Friday, the airline said, and warned the strike's effects could last into the weekend due to the throngs of passengers looking to rebook flights.

Air Canada, which has been involved in bitter and continuing labour problems over the past year with its pilots, mechanics, flight attendants and now ground crews, suspended three workers at Pearson on Thursday evening, setting off a chain of events that led to the illegal action.

The workers had apparently applauded sarcastically and heckled as Labour Minister Lisa Raitt walked through the airport on Wednesday. Her press secretary released a statement late Thursday that said Raitt was followed through the terminal at Pearson Airport and harassed by union members.

"The minister did not make any comments about the union members, nor engage in conversation with them," the statement said.

Raitt has angered workers by bringing in back-to-work legislation and sending their contract dispute with the airline to arbitration.

The employees were suspended for 72 hours. The striking workers said Friday morning that that's how long they would keep up their protest.

After several hours of noisy protests outside Terminal One, the striking workers relented and went back to work, but not before Air Canada had to cancel dozens of flights and left hundreds of passengers searching for their luggage.

Flights to Halifax, London, Ont., Cincinnati, Washington, D.C., Tokyo and dozens of other cities were scrapped.

A spokeswoman for the airline said Friday morning that an arbitrator had ordered an end to the strike, which began at about 10 p.m. Thursday. The carrier had originally called the arbitrator's ruling an injunction; the union says it was an agreement between both sides.

Air Canada spokesman Peter Fitzpatrick said later Friday that "there is an independent arbitrator agreed to by both parties and he issued a cease and desist order that carries the full weight of the law."

Union officials said the two sides agreed that if everyone went back to work, no one would lose their jobs, including the workers who reportedly harassed the labour minister. Raitt's office said the minister didn't file a complaint with police or with Air Canada.

37 workers fired, then reinstated

The union also revealed that a further 37 workers were fired for participating in the illegal strike. They will be reinstated as well.

Before the arbitrator's ruling, the labour minister's office told CBC News in an email that if the illegal walkout continued, "employees could face fines of up to $1,000 a day and the union could face fines of up to $100,000 a day."

Union spokesman Bill Trbovich said the union didn't sanction or condone the strike, and had cautioned workers they could be fired or fined for taking the illegal action.

The disruption led to anger and confusion at the airport. At one point, a male passenger spat in the face of a female airline worker.

In Montreal, hundreds of baggage handlers and other Air Canada workers walked off the job Friday morning for several hours in a show of support for their colleagues in Toronto.

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A passenger on her way to Fort Lauderdale from Montreal told CBC News she was already seated on the plane Friday morning when all the passengers were told to get off.

"As soon as everyone was seated, they asked us to disembark and said that the ground crew was using pressure tactics and to wait at the gate for further instructions," said Doris Juergens.

A similar situation developed at the Vancouver International Airport. Air Canada workers walked off the job for a short period. It isn't known if any flights were affected by the action.

The labour minister wasn't the only politician to feel the effect of the wildcat action.

Early Friday morning, federal Treasury Board president Tony Clement said his flight from Halifax had been delayed by two hours.

Travel chaos spreads nationwide Airline travel disrupted in other cities include: Calgary: Flights were cancelled just as families were set to embark on spring break. Nova Scotia: Flight cancellations left hundreds of passengers stranded, including a group of seven heading to a Canadiens home game in Montreal. "I feel sick to my stomach," one passenger told CBC News. "This is probably the last time I use Air Canada." New Brunswick: Airports in Fredericton, Moncton and Saint John reported flight delays and cancellations. A group of passengers at Moncton airport told CBC News they were frustrated by the lack of information coming from the company.

"Then we sat on the tarmac for about another hour or hour and a half. Now I don't have my bag," he said. "I think anybody who uses illegal job action to make their point is actually hurting their own cause. It's a huge inconvenience for the travelling public…You can't illegally take your frustrations out on management and inconvenience the travelling public."

With the NDP leadership convention beginning on Friday, many people from across Canada were scheduled to arrive in Toronto.

In Ottawa, delays and cancellations were reported.

Newfoundland and Labrador MHA Gerry Rogers said her flight from St. John's sat on the tarmac at Pearson for an hour before she could get off the plane, and she had yet to collect her luggage.

"We can't continue to have government interfering in these ways and breaking the backs of unions. This is about workers' rights, and I totally support this. If I have to wait in this airport for 10 hours for my luggage, so be it."

In a separate show of support, about a dozen protesters from various labour groups occupied Raitt's Milton, Ont., constituency office Friday.