A small number of Australian services are being impacted as Air Canada started cancelling flights overnight ahead of possible industrial action.

The airline reported an initial set of cancellations that affected several dozen long-haul overseas flights originating from Canada yesterday.

They include Air Canada’s flight from Vancouver to Sydney scheduled to depart last night and the returning flight due to leave Sydney tomorrow.

The union representing about 10,000 Air Canada flight attendants delivered a 72-hour strike notice on Wednesday, prompting the airline to respond with a lockout notice.

Mark Nasr, chief operations officer for Air Canada, said the carrier has begun a gradual suspension of operations.

“All flights will be paused by Saturday early morning,” he said.

Nasr said this approach will help facilitate an orderly restart “which under the best circumstances will take a full week to complete.”

He said a grounding will affect 25,000 Canadians a day abroad who may become stranded. They expect 500 flights to be cancelled by the end of Friday.

He mentioned that customers whose flights are canceled will qualify for a full refund. Additionally, the airline has coordinated with other Canadian and international carriers to offer alternative travel options “to the extent possible.”

The union stated that its primary concerns involve what it describes as flight attendants’ “poverty wages” and unpaid work when aircraft are not airborne.

Some flight attendants at the airline’s news conference on Thursday held up signs that read “Unpaid work won’t fly” and “Poverty wages = UnCanadian.”