A two-day strike by thousands of British Airways cabin crew is to go ahead next Tuesday and Wednesday.
It follows the break down of talks last night with unions on a dispute over pay and conditions.
BA is advising passengers to make alternative travel arrangements, as hundreds of both short and long-haul flights are likely to be cancelled.
The airline will operate no flights out of Heathrow.
All domestic and European flights to and from Gatwick will also be cancelled.
BA Chief Executive Willie Walsh said the company was bitterly disappointed that the union had refused to respond positively to serious proposals made on two crucial issues.
He called on the union to turn away from confrontation and take the dispute to the UK conciliation service, Acas.
As well as next week's strike, 72-hour walkouts are due to begin on 5 and 12 February.
