"We are making sure that this attempt to ruin Christmas for thousands of our customers fails," said Alex Cruz, BA's chief executive.

"Over the weekend we have been working on detailed contingency plans to ensure that we are able to operate our normal flight programme from all our airports on both Christmas Day and Boxing Day."

The announcement comes as BA holds talks at the conciliation service Acas with the Unite union in an attempt to avert the strike.

(Reporting by Michael Holden; editing by Stephen Addison)