Ground crew for 45 airlines at Pearson International Airport could be walking a picket line Thursday, potentially delaying flights.
Airlines that would be affected include Canjet, Air Transat, Air France, British Airways and KLM Royal Dutch.
The union representing 700 Swissport workers at Pearson filed a 72-hour strike notice on Monday and will ask its members to shoot down the company's final offer.
"We are suggesting that our members reject this offer," said Christopher Monette, a spokesman for Teamsters Local 419.
If this happens, the workers – including baggage and cargo handlers and cabin cleaners – will be able to walk off the job on Thursday night.
Monette didn't give specifics on why the union wants its members to reject Swissport's final offer, because the union hadn't yet presented it to its membership.
But the Teamsters recently raised issues with the company's decision to hire 250 temporary workers last May.
A statement issued by the Teamsters last week claimed the temporary workers only receive three to four days of training, rather than the three to four weeks afforded to their union counterparts.
"We don't think Swissport can basically do their jobs with workers that have no experience and poor training," Monette said, adding that the temp workers themselves aren't to blame.
"It's not their fault. They're being placed in an impossible situation," he said.
Swissport said that its workers all receive a minimum of 10 days of classroom training, as well as on-the-job instruction.
The union also claims that Swissport hired the 250 workers as a way of putting leverage on workers during the current round of contract talks.
"We're concerned that Swissport is willing to sacrifice airport safety to gain an upper hand at the bargaining table," Harjinder Badial, vice-president of Teamsters Local 419, said in a statement issued last week.
Swissport responded that it hired the temporary workers to help handle the summer travel rush, which it said it is allowed to do under the collective agreement.
"We are confident that protocols are being followed," Pierre Payette, Swissport Canada's vice-president of operation, said in a statement.
The Teamsters have filed a formal complaint with the Canadian Industrial Relations Board over the matter.
Among its claims are that there hasn't been a significant change in their members' workload and that Swissport gave the union a day's warning before it began hiring the 250 temporary workers.
Swissport said it wouldn't comment on the specifics of the union's allegations, citing the upcoming CIRB case.
Payette has said Swissport "categorically denies" the union's allegations.
"Swissport is fully confident, however, that the CIRB will dismiss these allegations as unsubstantiated and without merit," he said.
Swissport called its final offer to the union fair and competitive, and expressed disappointment that the union may strike.
"Regardless of this outcome, we remain open to ongoing negotiations and optimistic that an agreement will be reached with the union," the company said.
Monette says the union's members don't want to strike.
"Our members are hardworking folks – they want to keep working," Monette said. "But they're not going to allow themselves to be bullied by Swissport."