The airline said the action had "no shred of justification".
"British Airways is facing two years of record financial losses. Unlike other businesses, we have avoided compulsory redundancies and made changes designed to secure a long-term future for our company and our staff.
"For months, Unite has been claiming that we breached individual crew members’ contracts by making minor changes to onboard crew numbers on flights from Heathrow.
"The changes save us more than £60 million a year. We have made clear we would consider refinements of the changes, provided any additional cost was offset by other adjustments in the cabin crew budget.
"To date all proposals put forward by Unite fall significantly short of saving £60m a year.
"In addition, Unite’s plans would cut crew pay and allowances. The reductions required to generate sufficient savings would leave each crew member between £1,000 and £2,700 a year worse off. These proposals lack credibility, and Unite did not inform crew of them when it asked them to vote for a strike," BA claimed.
The airline said it would do "everything we can to protect our customers’ travel plans as far as possible".
BA plans to operate all flights from London City Airport, including long-haul services to New York, all long-haul services and about 50 per cent of short-haul from Gatwick and a "substantial part" of the Heathrow long-haul and short-haul schedule.
The carrier is in the process of obtaining seats on flights operated by other carriers.
"We will aim to give more details four or five days before the strike is due to begin when we will announce our revised flying programme."
BA said it remained available for further talks with Unite "at any time".
by Phil Davies
