Hundreds of thousands of travellers arriving at UK airports over Christmas have been warned of long delays with Border Force staff striking over pay and conditions.
They will walk out at Heathrow, Gatwick, Manchester, Birmingham, Cardiff and Glasgow airports, and the Port of Newhaven.
The military and civil servants have been drafted in to carry out passport checks.
The Border Force staff are striking from today until Boxing Day, 26 December, and 28 to 31 December.
