The federal government will intervene if Air Canada flight attendants go on strike and may change the Canada Labour Code if it finds it necessary, Labour Minister Lisa Raitt said Monday.

"Intervention is the first piece and then the second one is taking a look at the bigger problem and determining if there's any changes that need to be made," the minister told CBC's Wendy Mesley on Monday.

The 6,800 flight attendants have rejected a tentative deal reached between their union and the airline and are poised to go on strike at 12:01 a.m. Thursday, the union has said.

It was the second time in recent months that flight attendants have turned down a tentative agreement with the airline. They voted 87 per cent against ratifying the previous effort in August.

The rejection of two consecutive agreements shows there may be something wrong with the Canada Labour Code, Raitt said.

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"Maybe the union misjudged, maybe management misjudged, but to do it two times in a row is a warning bell and it's something that we have to take a look at," Raitt said.

"There's something wrong in this case, and does that mean there's something wrong in the code?" she said. "And if there is, what do we do about it? But the beginning part is analyzing the facts at hand to see if it's a one-off … or is it a case where the code, which is 100 years old, has to be taken a look at." Raitt said there are no changes planned, but that she is starting a process to see whether adjustments might be needed in the future.

"If we do have a problem and maybe it is a flaw in the system, we should discover it now and if we need to make changes we can make changes," the minister said.

Ian Lee, a labour expert at Carleton University in Ottawa, said he couldn't remember a labour minister making a similar comment.

"This will become the pretext and the context to legislate changes to the act that — knowing where this government is coming from — will make it more difficult to go on strike," Lee said.

Partial schedule

Air Canada said it hopes to avoid a work stoppage but will maintain a partial schedule in the event of a strike.

Customers who have already bought tickets to fly over the next six days will be allowed to change their travel dates at no charge, the airline said.

The Canadian Union of Public Employees said 65 per cent of the flight attendants who cast ballots voted to reject management proposals.

"We ask the federal government, in the strongest possible terms, to respect our right to collective bargaining and not intervene unilaterally in this dispute," Jeff Taylor, president of CUPE's branch for Air Canada flight attendants, said in a statement Sunday night.

After the first day of a three-day walkout by Air Canada's sales and support staff in June, Raitt indicated she would introduce back-to-work legislation. The airline and the Canadian Auto Workers union reached a deal the next day.

Taylor said this second rejection by attendants shows how frustrated they are with the airline after years of making concessions in wages and benefits.

Union leaders had predicted the second, revamped offer, reached Sept. 20, would be approved. They said they had managed to get about 80 per cent of what the membership was demanding in the areas of wages, pensions, crew rest, working conditions and work rules.