Thousands more British Airways passengers face a second day of cancelled or disrupted trips as cabin crew continue a five-day strike.
Many flights in and out of London's Heathrow Airport - BA's main hub - were axed on Monday, with knock-on effects elsewhere.
BA said it operated 60% of long-haul flights from Heathrow and 50% of short-haul.
It said Gatwick and London City airport were both unaffected.
The airline added that it had flown to 85% of its long-haul destinations and 100% of its short-haul ones.
The dispute is over pay, conditions and perks.
BA has accused union leaders of failing to take up an offer of further talks.
The airline said it was disappointed Unite had resorted to "negotiation through the media".
The Unite union is demanding the restoration of travel concessions to staff who took part in the last series of stoppages in March.
Unite's joint general secretary Tony Woodley told the BBC that the strike would have been suspended if those perks had been reinstated.
But BA said it had already agreed to do so once its deal was accepted in full.
Mr Woodley also accused BA boss Willie Walsh of wanting "regime change" at Bassa, the Unite branch representing crew.
Meanwhile, BA pilots have become embroiled in the dispute.
There have been suggestions from some cabin crew that a deal could not be done because pilots objected to travel perks being restored to staff who went on strike in March.
Jim McAuslan, general secretary of the British Airline Pilots' Association (Balpa), said: "It is nonsense to claim that pilots are doing anything to prevent a settlement.
"Indeed, to avoid making a bad situation worse, we have stayed neutral throughout this dispute despite the huge damage to the company's reputation and the very real risk that it poses for the future of all employees.
"We have encouraged both sides to reach agreement," Mr McAuslan added.
Talks were brought to an abrupt end on Saturday evening when left-wing protesters gatecrashed the venue where negotiations were being held.
On Sunday, BA issued a statement calling on Mr Woodley to call off the strike and return to the negotiating table.
"We had agreed to a request from [conciliation service] Acas to meet this afternoon and are surprised that Unite did not take advantage of this," it said.
"We have already offered to reinstate travel concessions to cabin crew once all elements of our offer have been implemented.
"Of more concern to us is Tony Woodley's comment to the media that he wants to revisit certain proposals in our offer, when previously he had indicated that these were agreed."
The statement went on to again blame Bassa for the failure to reach an agreement.
BA has said it plans to fly more than 60,000 customers a day during the strike, operating 60% of long-haul flights and 50% of short-haul services from Heathrow.
It says all flights at London Gatwick and London City will operate as normal.
The airline said it had leased as many as eight aircraft with pilots and crew from other UK or European carriers.
BA was granted a court injunction last week preventing the strikes after the High Court ruled that the Unite union had not reported results of its strike ballot correctly to members.
However, this was overturned on Thursday following an appeal by the union.
In addition to this week's strike, which started at midnight on Sunday, two further five-day walkouts by Unite members are scheduled to begin on 30 May and 5 June.
The long-running dispute between BA and Unite cabin crew members centres began on jobs, pay and working conditions.
However, after striking workers had their travel concessions removed following the walkouts in March, with others facing disciplinary action, Unite said these issues also had to be addressed in any successful agreement.
Numerous BA cabin crew members rely on travel perks - where they pay 10% of normal fares - to commute to work from UK cities outside London, or even from mainland Europe.