A "substantial" number of flights will still fly from Heathrow, BA says
British Airways has said 1,000 staff have volunteered to work as cabin crew if a threatened strike goes ahead.
It would also hire up to 23 fully crewed planes from a charter company to help run flights from Heathrow in the event of a strike.
During an internal briefing for staff, BA chief executive Willie Walsh warned he would not reverse cabin crew cuts.
The changes were imposed in November without agreement, which triggered the strike threat.
Mr Walsh said in his address that the two sides had had only two hours of talks in the past two weeks, which Unite dismissed as "utter nonsense".
BA says that it will be able to operate all flights from London City Airport, and all long-haul services from Gatwick, if a strike is called.
A "substantial number" of long- and short-haul flights from Heathrow would still operate.
'Business as usual'
BA was praised in some quarters for training staff to cover for cabin crew.
"This latest development is an interesting example of the innovative ways businesses can keep functioning in the face of staff strikes," said Guy Lamb, employment partner at DLA Piper.
"Unlike the challenge to Royal Mail's use of agency staff, there is nothing to stop an employer using their existing workforce to cover the roles of striking colleagues."
He said that as long as BA complies with health and safety regulations and working time directives, and does not breach employees' contracts of employment, "cross training staff can be a very effective way of maintaining 'business as usual' during periods of industrial action".
In its dispute with Royal Mail last year, the Communication Workers Union (CWU) threatened legal action over the company's policy of employing agency workers to deal with the backlog of mail.
BA is losing money and needs to cut costs to make a profit.
It introduced a number of measures last November, including reducing the number of crew on long-haul flights and bringing in a two-year pay freeze from 2010.
It is these measures that have angered BA staff. Last week, they voted in favour of strike action.