UK Border Force workers at several major British airports including the country's busiest, Heathrow, will go on strike for eight days this month in a dispute over pay, threatening to slow processing of passengers arriving from abroad during the holidays.

A BA spokesperson said the carrier was working with the government and airport "to ensure that we play our part in ensuring our customers are able to travel as planned at this important time of year."

A Virgin Atlantic spokesperson also said it was working closely with government to "minimise the impact of Border Force strikes on our customers' journeys."

The strikes, from Dec. 23-26 and 28-31, come at one of the busiest periods for airlines, and the flights affected were already busy. Heathrow is a hub for both airlines, and BA is the dominant carrier.

British Airways and Virgin Atlantic have also given customers the option of extra flexibility to shift their travel to a non-strike day, and flight schedules - as well as restrictions on tickets - are being kept under review.

"We intend to operate our schedule as planned, with additional flexibility to allow customers to change their flight dates if they wish to avoid arriving on strike days," the Virgin Atlantic spokesperson said.