Security staff at Heathrow Airport have announced an escalation of strike action, with walkouts to take place nearly every weekend from mid-June to the end of August.
Members of Unite are embroiled in a long-running dispute over pay which has led to previous industrial action.
From 24 June, 31 days of strikes will take place by more than 2,000 security staff.
The workers will be on strike on:
• June 24, 25, 28, 29 and 30
• July 14-16, 21-24, and 28-31
• August 4-7, 11-14, 18-20 and 24-27