Staff on London Overground are to stage a fresh strike in a dispute over pay.

Members of the Rail, Maritime and Transport (RMT) union working as travel safe officers will walk out for 24 hours on May 16 following a stoppage earlier this month.

The workers, employed by STM Security, are planning other forms of industrial action short of a strike, saying they face a pay freeze.

RMT general secretary Mick Cash said: "Travel safe officers offer security for passengers and staff against a background of increasing anti-social and violent behaviour on the railways.

"Despite previous rock-solid strike action, the company still refuse to listen and have left us with no option but to confirm a further phase.

"Our members do an important job on London Overground and deserve to be paid properly for the work that they do.

"A pay freeze for workers on a low wage is an insult and represents a pay cut in real terms."

London Overground operator Arriva said: "The industrial dispute it is a matter between the RMT union and STM Security, which supplies travel safe officers on the London Overground.

"STM has taken steps to put a comprehensive plan in place to minimise impact on customers travelling on London Overground services and to maintain high levels of safety and security."

A spokesman for STM Group said: “STM are disappointed in the action taken, we remain willing to work with all parties to resolve this dispute. We have made ourselves available for further discussions with the RMT Union.”