London: British Airways canceled hundreds of flights as chances dwindled for a breakthrough that would avert the first pilots’ strike in decades.

After the weekend yielded little progress toward a resolution of the pay dispute, a British Airways spokeswoman said Sunday that the airline had canceled “the vast majority” of its 850 daily flights on Monday and Tuesday.

The disruptions will affect mainly London, where BA operates from its hub at Heathrow airport and also Gatwick. The outages will also extend to other locales such as Edinburgh, though London City, popular with business travelers, won’t be affected as those flights are operated BA’s CityFlyer affiliate.

Pilots vowed to strike following a breakdown in talks over a new contract. The airline has accused the British Airline Pilots’ Association union of not acting in good faith by making “an eleventh hour inflated proposal” which would cost an additional 50 million pounds ($62 million).

Balpa had put forward a new contract proposal last week and pledged to call off the walkout if management returned to the bargaining table.

Both sides have said they’re open to more talks, though the airline insists that terms of the latest union proposal amount to preconditions it won’t accept.

The airline has sent an email warning the pilots that anyone who goes on strike will lose generous travel perks for themselves and their families for the next three years, the FT reported.

The strike would be the company’s first involving pilots since the 1970s and could cause travel chaos for customers at the tail end of the busy summer season. Passengers that are affected have been rebooked with other airlines or given alternate dates to fly, the BA spokeswoman said. Others have been given refunds.

The current demands relate to pay, profit sharing, and a share-awards program, and come after cockpit crew took salary cuts in the wake of the financial crisis to help bolster the airline’s finances, according to the union.

The union called for the action after mediated talks with management at the state-backed Advisory, Conciliation and Arbitration Service ended without a deal. Cockpit crews voted to strike by a 93% majority in a poll in July, with the carrier saying the disruption could cost 40 million pounds a day.

Balpa is also campaigning at Ryanair Holdings Plc, where U.K. pilots plan to walk out for an additional seven days. Five days of strikes failed to disrupt schedules or bring the discounter - which uses many non-unionized pilots on contract - back to the bargaining table.