A three-day strike by British Airways cabin crew affecting thousands of travellers was set to start at midnight British time — 7 p.m. ET — Friday after last-ditch talks between the airline's management and union leaders collapsed.

British Airways CEO Willie Walsh said it was "deeply regrettable" the union declined to accept a proposal on pay and working conditions, adding BA will withdraw the offer once the strike begins.

A British Airways Boeing 747 taxis away from Terminal 5 at London's Heathrow Airport in August 2009. Talks with a cabin crew union aimed at averting a strike have broken down. (Mark Lennihan/Asociated Press Photo)

"Tens of thousands of BA people stand ready to serve our customers," Walsh said. "BA will be flying tomorrow."

Tony Woodley, the Unite joint general secretary, said the airline "does not want to negotiate and ultimately wants to go to war with this union."

Unite represents 12,000 cabin crew members.

Some flights have already been cancelled.

British Airways argued that its proposals — including a pay freeze this year, a switch to part-time work for 3,000 staff and a reduction in cabin-crew sizes from 15 to 14 on long-haul flights from Heathrow airport — are critical for its survival. Unite argues it was not properly consulted on the changes.

The union has scheduled a second, four-day walkout to begin March 27 and has said more strikes will be scheduled for after April 14 if the dispute is not resolved. Unite has made a pledge not to walk out over the busy Easter period in early April.

BA estimated to have lost $38M

Analysts estimate that BA has already lost more than $38 million Cdn because of cancelled tickets and the cost of contingency plans, which include leasing fully crewed planes from other airlines.

Those contingency plans allow for the operation of enough flights for around 65 per cent of its booked passengers across its network.

A total of 1,100 flights out of the 1,950 scheduled to operate during the first three strike dates will be cancelled.

More than 60 per cent of the carrier's long-haul services into and out of London Heathrow and 30 per cent of short-haul flights will operate.

The prospect of travel chaos in Britain in the run-up to the Easter break also intensified with news that railway signal workers voted in favour of a strike, joining rail maintenance workers. The Rail Maritime and Transport union has not called dates for a walkout of both groups of workers but has refused to rule out the Easter long weekend.

The prospective industrial rest is an unwelcome turn of events for the ruling Labour Party on the eve of a national election.

With files from The Associated Press