Air Canada suspended operations as more than 10,000 Air Canada flight attendants went on strike early Saturday after a deadline to reach a deal passed, leaving travelers around the world stranded and scrambling during the peak summer travel season.

Canadian Union of Public Employees spokesman Hugh Pouliot confirmed the strike had started after no deal was reached, and the airline said it halted operations.

A bitter contract fight between Canada’s largest airline and the union representing 10,000 of its flight attendants escalated Friday as the union turned down the airline’s request to enter into government-directed arbitration, which would eliminate its right to strike and allow a third-party mediator to decide the terms of a new contract.

A complete shutdown will impact about 130,000 people a day, and some 25,000 Canadians may be stranded abroad daily. Air Canada operates around 700 flights per day.

Flight attendants walked off the job around 1 a.m. EDT on Saturday. Around the same time, Air Canada said it would begin locking flight attendants out of airports.

Both sides say they remain far apart on the issue of pay and the unpaid work flight attendants do when planes aren’t in the air.

“We are heartbroken for our passengers. Nobody wants to see Canadians stranded or anxious about their travel plans but we cannot work for free," said Natasha Stea, a Air Canada flight attendant and local union president.

The attendants are about 70% women. In a press briefing on Saturday, Stea said Air Canada pilots, who are male dominated, received a significant raise last year and questioned whether they are getting fair treatment.

The airline’s latest offer included a 38% increase in total compensation, including benefits and pensions over four years, that it said “would have made our flight attendants the best compensated in Canada.”

But the union pushed back, saying the proposed 8% raise in the first year didn’t go far enough because of inflation.

“We’re the national carrier and we have people operating in poverty. Like that’s disgusting, that's very problematic,” Wesley Lesosky, President of the Air Canada Component of CUPE, said at a news conference.