Workers at Heathrow Airport Limited (HAL) struck on Friday of last week and planned further strikes on Tuesday and Saturday this week.
Further action is set for 16 and 18 February.
The bitter dispute is over the company’s decision to fire and rehire its entire workforce to ram through inferior wages and conditions.
Workers, who are in the Unite union, previously struck for four days in December.
The decision to fire and rehire its workforce will see HAL workers’ pay cut by up to 25 percent—up to £8,000 per year.
Workers on strike include firefighters, engineers, security, baggage operations, central terminal operations, landside and airside operations.
The Unite union members are then set to walk out for 48 hours on 15 February and for a further 24 hours on 18 February.
The 50 scaffolders are employed by contractor Brand Energy.
The 20 security guards, in the Unite union, have been striking since mid-December.
Bosses have refused to offer more than £9.30 for security officers, who are fighting for an increase to £12 an hour.
A long-running battle goes on at Actavo
The workers are fighting a Lib Dem council
The Tories are targeting refugees and migrants