Heathrow Airport has said some passengers may face security delays over the Easter holidays due to pay strike action.
More than 1,400 security officers in the Unite union, who work for Heathrow Airport, have started 10 days of industrial action.
Talks at the eleventh hour on Thursday broke down without resolution.
It threatens disruption at the UK’s biggest airport at the start of the Easter school holidays.
The strike includes security guards at Terminal 5, which is used only by British Airways, and baggage handlers. Unite accused the airport of a real-terms wage cut.
Heathrow said it had offered a 10% pay rise from January 1, including a lump sum payment of more than £1,000.
The airport said contingency plans were keeping the airport operating as usual, but British Airways canceled around 70 flights for Friday.
This includes flights that have been canceled due to strikes, and cancellations for other reasons, such as bad weather and an air traffic control strike in France.
Picket lines were mounted outside the airport and Unite said the strike was “well supported”.
Are you a security officer on strike at Heathrow, or a passenger worried about your travel plans being disrupted? Share your experiences.
Security checks
The next few days are expected to be busy as people leave for the Easter holidays.
Before the strike, Heathrow asked airlines to stop selling tickets and allow customers to change travel dates.
British Airways pre-emptively canceled 300 flights and Virgin Atlantic confirmed it had limited new ticket sales and introduced a flexible policy.
The strike reduced the number of security staff available at the airport on what would normally be a very busy weekend.
Heathrow said it was deploying 1,000 extra colleagues and its management team to assist passengers.
Travelers should check their flight before traveling to the airport, arrive at Heathrow no earlier than two hours before short-haul flights and three hours before long-haul flights, and be prepared for security , the airport said.
Passengers will only be allowed through security with two items of hand luggage to aid flow.
The aviation industry is under pressure from the government and the industry regulator to avoid a repeat of last year’s Easter queues, delays and cancellations, which were largely caused by staff shortages.
A leaked letter to businesses from the Civil Aviation Authority and Department for Transport, seen by the BBC, says it is unacceptable for consumers to face the same level of disruption this year.
Airlines and airports told the BBC they were confident they would have enough staff at this time, although external factors such as strikes in France affecting air traffic control could cause issues.
