Security guards at London's Heathrow airport will strike for 31 days this summer over pay, their union Unite announced Wednesday as it warned of travel chaos during the peak season.

More than 2,000 security officers at Terminals 3 and 5 will begin a new series of walkouts on June 24 through to August 27, Unite said in a statement.

The latest planned industrial action, billed by Unite as a "summer of strife", is timed to coincide with busy travel periods.

It includes the Muslim festival of Eid al-Adha in late June, the start of school holidays in late July and the long holiday weekend at the end of August.

"Delays, disruption and cancellations will be inevitable as a result of the strike action," said Unite regional officer Wayne King in a statement, as the union urged management to make a "fair" pay offer.

Over the past year, Britain has been plagued by strikes, also by railway and postal workers as well as nurses and teachers, as high inflation erodes the value of wages.

"Unite is putting Heathrow on notice that strike action at the airport will continue until it makes a fair pay offer to its workers," said Unite general secretary Sharon Graham.

UK annual inflation slowed to a 13-month low in April, but remains elevated at 8.7 percent as soaring food prices offset weaker energy costs, recent official data showed.

Heathrow, one of the world's largest airports, is owned by a consortium led by Spanish construction giant Ferrovial.

The consortium also includes sovereign wealth funds from China, Singapore and Qatar as well as North American shareholders.