VANCOUVER — A mistake by Air Canada in offering a package of flights at just 10 per cent of the value has triggered a proposed class-action lawsuit by customers who thought they got an amazing deal.

Court documents, filed in both Quebec and British Columbia, stated the flight pass was offered between Aug. 25 and Aug. 28 at just under $800, but customers were told days later the cost of 10 one-way business-class flights in the western U.S. or Canada was actually $8,000.

The documents said Air Canada (TSX:AC.A) refused to live up to its contractual obligations and illegally removed the flight passes.

Garrett Munroe, a lawyer with Munroe and Company, the B.C. firm behind the legal action, said the lawsuit could involve thousands of people, but only Air Canada knows exactly how many people purchased the deal.

“Our view here is that Air Canada has made an enforceable contract, it delivered the flight packages to consumers and it has improperly taken them away,” he said in an interview.

“Air Canada is duty bound and legally obligated to honour its bargain.”

Nothing has been proven in court.

Air Canada spokeswoman Angela Mah wouldn’t comment on the lawsuit but released a previous statement that said a “computer-loading error” was responsible for the “temporary mispricing.”

“Air Canada has contacted purchasers to apologize and provided a refund,” the statement said.

The airline said any flights already booked with the pass would be honoured.

But Munroe said they want the courts to force Air Canada to live up to its original bargain.

“They say it’s a mistake, but how much recklessness is reasonable in terms of allowing the website to show an offer that they don’t intend to be bound by,” he said.

“It would create a significant amount of confusion and uncertainty in the marketplace if consumers were conducting business with the possibility that the merchant is going to come back and attempt to undo the deal that it made.”

It was an attractive price and people bought the package expecting to be able to use it, he said.

“It shouldn’t be up to the consumer to second-guess the merchant’s motivations in advertising a particular product for sale at a particular price.”

The next step is to ask the courts in both provinces to certify the class-action lawsuit that would represent all those who ask to be part of it.

“Rather than having tens-of-thousands of lawsuits, it can be dealt with as one,” Munroe noted.

Even if Air Canada decided to honour the agreements for the same price now, that doesn’t take care of the legal action because the consumer has lost out on potentially planned trips, he said.