About 800 airline food service staff at Toronto's Pearson airport went on strike Tuesday, leaving thousands of passengers without meals.

Gate Gourmet employees voted 96 per cent against an offer from the Swiss-owned travel catering company on Monday night, Teamsters Canada said.

The workers cook, package and deliver food and beverages to planes for in-flight service.

The job action, which kicked off a minute past midnight, affects travellers on Air Canada, WestJet and a majority of flights to and from the country's busiest airport.

"Our members are trying to survive this cost of living crisis and support their families through these difficult times. That's what this is about," said Martin Cerqua, lead negotiator for the union local.

He said employees, many of whom earn between $18 and $20 per hour, are asking for a living wage and earnings on par with workers across the country.

For example, Gate Gourmet employees who unload tray carts and wash dishware and cutlery at the Vancouver airport make $6 per hour more than their co-workers at Pearson, he said.

"We’ve fallen so far behind," Cerqua said from the picket line on the fringes of the airport.

"It’s a dirty, difficult, physically demanding job."

Gate Gourmet is the largest airline catering company operating out of Toronto, with clients that include Air Canada, WestJet, United Airlines and Delta Air Lines. Owned by Gategroup, it operates in more than 135 locations in 33 countries, according to its website. Those figures include eight airports in Canada.

The caterer said its latest offer was "fair and market-competitive," laying out a 12 per cent pay raise over three years. Current wages range between $17.69 and $25.10 per hour, said Elaine Dray, Gategroup's head of human resources in North America.

Rather than considering only wage disparities, she said the company looks at overall compensation.

"They have higher base rates, yes," she said of employees in Vancouver. "However, they have a different total compensation package such as benefits, premiums, vacation."

Asked whether workers out of Pearson make a living wage, Dray replied: "I'm going to hesitate here by asking, how do we all define a living wage?

"We are providing them with a good wage that is in comparison to our competitors and other frontline jobs out there," she said.

Air Canada said short-haul flights will be most affected.

Economy-class customers on flights under two hours will receive a pretzel or cookie along with water, while those in business class will not enjoy their usual hot meal service. Passengers on flights over two hours within North America can grab a snack and beverage, with alcohol and some meal options available for purchase.

"We do not anticipate an impact on our international flights" —  the U.S. not included — said Air Canada spokesman Peter Fitzpatrick in an email. Impacted customers will be notified, he added.

WestJet said flights operating through Pearson on Boeing 737 planes — the vast majority of its fleet — may experience "an inconsistent food or beverage offering" starting Tuesday.

"We are advising guests travelling to or from Toronto to plan ahead and bring an extra snack and/or beverage for their journey," said spokeswoman Madison Kruger in an email.

For transatlantic flights, the airline is giving customers an "alternative option" or vouchers to buy food at the terminal before departure, on top of free pretzels or cookies on board, she said.

Teamsters Canada said Gate Gourmet has failed to sufficiently increase pay cheques after a wage freeze during the COVID-19 pandemic. One proposed wage increase amounted to an extra 89 cents per hour, Cerqua said.

The company has also cut staffing levels — particularly for wide-body planes with 200-plus seats — which he blamed for a rise in workplace accidents. 

"That makes a high-pressure job even more difficult," he said, claiming that seven hi-lift truck drivers were injured in the past three months.

"Those drivers work in extreme conditions: cold, rain, snow, sleet, extreme heat," he added.

Gategroup's Dray said safety is "one of our No. 1 priorities," but said she did not have workplace injury statistics on hand.

The company employs fewer workers at Pearson than in 2019, but that is because business has not returned to pre-pandemic levels, she said.

"We want to get a deal done with the union. We want to get back to regular production."