Air Canada flight attendants demonstrated Thursday outside the constituency office of MP Lisa Raitt, the federal labour minister, after they were barred from going on strike.

About 100 union members and supporters gathered, sang and chanted at Raitt's office in Milton, Ont., west of Toronto.

The flight attendants are upset after Raitt referred a contract dispute between them and the airline to the Canada Industrial Relations Board, asking the board to examine whether a walkout would affect Canadians' health and safety.

The move blocked the flight attendants from going on strike at 12:01 a.m. Thursday as they had planned.

Meanwhile, Air Canada said flights are operating as scheduled.

The airline, which recently filed its own complaint about the union with the CIRB, said in a statement Thursday that it was "business as usual at Air Canada and all flights will continue to operate as scheduled."

The CIRB said Wednesday that it is being asked to determine, under Section 87.4 of the Canada Labour Code, "whether any services need to be maintained, in the event of a strike or lockout, to prevent an immediate and serious danger to the safety or health of the public."

The board said it is also being asked to look at whether the "rejection of two tentative agreements recommended by the union created conditions that are unfavourable to the settlement of the industrial dispute at hand."

While the board reviews the issues, the flight attendants are not allowed to strike and management is not allowed to lock out workers.

'Great relief,' air traveller says

Traveller Coleen Karr told CBC's Jeff Semple that she felt "great relief" when she learned that there wouldn't be a strike.

"It takes a little stress off," she said Thursday from Toronto's Pearson International Airport.

CUPE, the union representing the flight attendants, has accused the government of conducting an "unwarranted attack" on the flight attendants' collective bargaining rights. CUPE also accused Raitt of misusing the federal labour board.

Meanwhile, Air Canada is filing an unfair labour practices complaint against CUPE with the CIRB. The airline is complaining that the union leadership doesn't appear to be reflecting the wishes of the membership, among other concerns.

The airline said the union's inability to properly represent their members is causing Air Canada significant harm, because the threat of a strike discourages people from buying Air Canada tickets. The company said it was willing to come to an agreement, but believes the union has misrepresented the elements of an agreement which would likely be ratified by membership.

The CIRB is an independent, quasi-judicial body that investigates complaints about contract disputes and can take weeks to report its findings. Back to work legislation for the Air Canada-CUPE dispute is already on the Parliamentary notice paper, but now that the CIRB is involved, the government will likely wait until that report before acting. Parliament returns from its Thanksgiving break on Monday.

Airline uncertainty means more work for travel company

Jason du Sautoy, director of supplier relations at the travel agency Flight Centre, said the contract dispute had created some challenges in the travel agency community in recent weeks, but he said it was back to "business as usual" at the busy travel company.

"Uncertainty is the worst thing we can face, really," he said. "Partly because from a purely operational standpoint, each sale takes twice as long as it might because people start investigating alternatives to Air Canada."

He said the uncertainty also meant that many travellers who had already booked on Air Canada were calling back to get more information or try to change their bookings.

Al Price, a Burlington, Ont., man who was heading to Calgary for business, said he tried to change airlines when he heard about the contract disputes.

"We tried to switch over to WestJet, but of course it was all sold out," Price said, adding that he doesn't think airline workers should be allowed to strike because of the potential disruption to the economy.

"I think from now on I'll start flying alternative airlines," he said. "Just because it's such a hassle with these guys and the service here is not worth it."

Union willing to resume talks

CUPE has negotiated two contracts with Montreal-based Air Canada in the last three months but both have been rejected by the flight attendants. The workers are angry about the airline's plans for a discount carrier that would require lower wages for new hires and the company's position on pensions and other work issues.

The union said in a statement Wednesday that it is ready to head back to the bargaining table to try to reach a new deal with management.

The federal government has used back-to-work legislation — or the threat of it — twice in recent months. The government said it would legislate Air Canada customer service staff back to work in June, but management and the union representing the 3,800 customer service and sales agents reached a deal shortly after the government tabled back-to-work legislation.

Thousands of postal workers were legislated back to work later in June. CUPW, the union representing the workers who were locked out following a rotating strike said Wednesday that it is challenging the constitutionality of the back-to-work law.

With files from The Canadian Press