Border Force staff at Britain's busiest airport, Heathrow, will go on strike on May 31, June 1 and 2, a busy travel time during the country's school holidays, as they continue their protest over changes to their working conditions.

The Public and Commercial Services (PCS) union said staff in terminals 2, 3, 4 and 5 would also refuse to work overtime for three weeks from June 4, taking action against Britain's interior ministry which has changed their roster system.

About 300 border force staff staged a four-day walkout at the end of April and in early May.

Heathrow has previously said it has contingency plans in place for any strike action, and can avoid any impact to passenger journeys.

(Reporting by Sarah Young; editing by Michael Holden)