Unions representing around 2,000 security officers at London Heathrow have confirmed another 31 days of strikes this summer.

This time the industrial action could impact travellers at Terminal 5 and also at Terminal 3. In previous strikes, Terminal 3 workers have not been involved.

Unite said the strikes will heavily impact British Airways flights at Terminal 5 and could also cause disruption, delays and cancellations with a number of other airlines, including Virgin Atlantic, Emirates, Qatar, United, American and Delta.

The walkouts are planned for the following dates:

• June 24, 25, 28, 29, 30
• July 14, 15, 16, 21, 22, 23, 24, 28, 29, 30, 31
• August 4, 5, 6 , 7, 11, 12, 13, 14, 18, 19, 20, 24, 25, 26, 27

A Heathrow spokesperson said it would do everything it can to minimise disruption.

“Unite has already tried and failed to disrupt the airport with unnecessary strikes on some of our busiest days and we continue to build our plans to protect journeys during any future action,” said a spokesman.

“The simple fact remains that the majority of colleagues do not support Unite’s strikes. There is a two-year inflation-beating pay rise ready for colleagues, if only Unite would allow them to have a say”.

Clive Wratten, CEO of the Business Travel Association, said: “These strikes are maliciously targeted to spoil summer getaways. They will also cause a significant loss of confidence for business customers.

“We hope that Heathrow will cope as well this summer, as it has done in the face of repetitive strike action to date.”

Guy Snelgar, Global Business Travel Director of The Advantage Travel Partnership, added: “These new strikes and the ongoing disruption to travel in the UK with ongoing rail and border force strikes continues to have a detrimental effect on how travellers view the travel industry and the plans they make.

“This has a particularly detrimental effect on corporate travellers who are becoming increasingly less reliant on UK travel systems such as rail networks and airports to plan for meetings and are instead getting in their cars or holding virtual meetings as required.”

The planned strikes are in response to a long-running dispute over pay with employer HAL.

Unite Regional Co-ordinating Officer Wayne King said: “Delays, disruption and cancellations will be inevitable as a result of the strike action. But this dispute is completely of HAL’s own making.

“The company has been given numerous opportunities to make an offer that meets our members’ expectations and so avoid another period of damaging strike action. Sadly, HAL has stubbornly refused to take this opportunity.”

Border Force staff at Heathrow, represented by the PCS union, held a series of separate walkouts earlier this year.