Strikes planned for Christmas were suspended after the new offer was made but members rejected it by 7-1.

The strike affects "mixed fleet" staff who joined after 2010 and account for 15% of the total cabin crew.

BA said it planned to "ensure that all our customers travel to their destinations".

It said further details for customers would be published on Friday 6 January, once it had finalised contingency plans.

"We are extremely disappointed that Unite has once again chosen to target our customers," the company said.

"We are now focused on protecting our customers from this unnecessary and completely unjustified action."
'Meaningful talks'

The dispute concerns about 4,000 staff who have joined the airline since 2010 on "mixed fleet" contracts, who do not feel they are paid enough. About 2,500 of them are Unite members.

Earnings were advertised between £21,000 and £25,000 but, in reality, start at just over £12,000 plus £3 an hour flying pay, Unite said.

The union said its members rejected the new offer by 7-1.

"British Airways is needlessly provoking strike action by refusing to extend the mandate of the strike ballot and allow meaningful talks to take place," Unite's national office Oliver Richardson said.

"Instead of listening to why its mixed fleet cabin crew rejected the offer negotiated at Acas, British Airways has sought instead to try and bully a workforce of young men and women who are trying to eke out a living on poverty pay."

However, he added that the union was "hopeful that a negotiated settlement which meets our members' aspirations can be achieved" and urged BA to "engage constructively".