Border Force staff at Britain's busiest airport, Heathrow, are set to strike for four days to protest changes to their working conditions.
The Public and Commercial Services (PCS) union said more than 300 members of staff would stop working early on Monday in terminals two to five.
A separate union, Unite, has said its workers will go on strike at Heathrow from May 7 to May 13 over plans to outsource hundreds of roles.
Surging inflation and a tough cost of living crisis have led to repeated bouts of strike action in Britain in recent years, with teachers, nurses, train workers and airport staff walking out to protest against low pay and conditions.
Heathrow has previously said it has contingency plans in place for any strike action and can avoid any impact to passenger journeys.
Australian Associated Press
