The Canadian Union of Public Employees, which represents 6,800 Air Canada flight attendants, said on Saturday that members voted overwhelmingly against the deal.

The airline and union negotiators reached the tentative pact on compensation and benefits on Aug. 1. The previous contract expired on March 31.

After the deal was announced, the airline said it would not reveal any details about the contract until after it was ratified.

Turnout was heavy during the 10 days of voting, the union said, with nearly 79 percent of membership participating.

"The results send a strong message to the company," Jeff Taylor, president of the Air Canada unit of CUPE, said in a statement.

"We negotiated the best deal we felt we could in the current political context. But it wasn't enough and we will take that message back to the employer in the strongest possible way."

Taylor said the union would meet with the carrier as soon as possible to resume negotiations.

Air Canada, which competes in the Canadian market with WestJet Airlines and closely held Porter Airlines, said the rejection would have no effect on service.

"Air Canada confirms it's business as usual for the airline," it said in a statement.

The union said it would meet with members over the coming days, and that a strike vote will take place between September 4 and September 13.