Air travelers faced potential delays at UK airports on Friday as government employees who check passports went on strike in the latest in a series of strikes for wages amid a cost-of-living crisis.
The Border Force personnel strike was to continue until the end of the year, with the exception of next Tuesday.
Hundreds of thousands of passengers could be affected, although the British government said it was preparing military personnel and workers from other public services to help at airports.
The strikes are putting pressure on the conservative government of Prime Minister Rishi Sunak, which is rejecting demands for substantial pay increases for public sector workers.
Inflation stood at 10.7% in November, driven by food and energy prices in the wake of the COVID-19 pandemic and the Russian invasion of Ukraine.
Thousands of NHS nurses walked off the job on Tuesday in their second 24-hour strike this month. Ambulance drivers, paramedics and dispatchers also went on strike earlier this week and plan another strike on December 28.
Postal deliveries, road maintenance and driving tests are also disrupted by strikes.
The labor unrest is expected to continue into the new year, when more strikes are planned.