TORONTO — Air Canada said Tuesday it will gradually restart operations after reaching an agreement with the union for 10,000 flight attendants to end a strike.

The union first announced the agreement early Tuesday after Air Canada and the union resumed talks late Monday for the first time since the strike began over the weekend. The strike is affecting about 130,000 travelers a day at the peak of the summer travel season.

Canada’s largest airline said flights will start resuming Tuesday evening.

The union said the agreement will guarantee members pay for work performed while planes are on the ground, resolving one of the major issues that drove the strike.

“Unpaid work is over. We have reclaimed our voice and our power,” the union said in a statement. “When our rights were taken away, we stood strong, we fought back — and we secured a tentative agreement that our members can vote on.”

Chief executive Michael Rousseau said restarting a major carrier is a complex undertaking and said regular service may require seven to 10 days. Some flights will be canceled until the schedule is stabilized.

“Full restoration may require a week or more, so we ask for our customers’ patience and understanding over the coming days,” Rousseau said in a statement.

The airline said mediation discussions “were begun on the basis that the union commit to have the airline’s 10,000 flight attendants immediately return to work.” Air Canada declined to comment further on the agreement until the ratification process is complete. It noted a strike or lockout is not possible during this time.

The agreement followed the union’s declaration that the flight attendants wouldn’t return to work even though the strike was declared illegal.

Earlier, Air Canada said rolling cancellations would now extend through Tuesday afternoon after the union defied a second return-to-work order.

The Canada Industrial Relations Board had declared the strike illegal Monday and ordered the flight attendants back on the job. But the union said it would defy the directive. Union leaders also ignored a weekend order to submit to binding arbitration and end the strike by Sunday afternoon.

The board is an independent administrative tribunal that interprets and applies Canada’s labor laws. The government ordered the board to intervene.

Labor leaders objected to the Canadian government’s repeated use of a law that cuts off workers’ right to strike and forces them into arbitration, a step the government took in recent years with workers at ports, railways and elsewhere.

“Your right to vote on your wages was preserved,” the union said in a post on its website.

Air Canada operates around 700 flights per day. The airline estimated Monday that 500,000 customers would be affected by flight cancellations.

Aviation analytics firm Cirium said that as of Monday afternoon, Air Canada had called off at least 1,219 domestic flights and 1,339 international flights since last Thursday, when the carrier began gradually suspending its operations ahead of the strike and lockout that began early Saturday.

Toronto’s Pearson International Airport, Canada’s largest, said it will deploy additional staff to assist passengers and support startup operations.

Passengers whose flights are impacted will be eligible to request a full refund on the airline’s website or mobile app, according to Air Canada.