Transport workers on London Underground and the Overground network will take 24-hour strike action in separate disputes later this month, the biggest rail workers’ union confirmed on Tuesday.

Members of the Rail, Maritime and Transport union will walk out on August 19, in between strikes on August 18 and 20 on Network Rail and 14 train operators in the long-running row over pay, jobs and conditions.

Tube workers have been locked in a dispute over pensions and jobs for more than six months while Overground workers employed by Arriva Rail London will strike over pay.

The union gave Transport for London until Tuesday to give assurances that there would be no job losses, no detrimental changes to pensions and no changes or imposition of working conditions.

RMT members on Arriva Rail London have rejected a 5% pay offer.

RMT general secretary Mick Lynch said: “This strike action by our members on LU and the Overground is yet another demonstration of how transport workers refuse to accept a raw deal.

“TfL have had ample opportunity to be transparent about the funding they will receive and to give tube workers the assurances they need.

“Yet they have totally failed to give those guarantees.

“And Arriva Rail London, a company swimming in money, refuses to give our members a pay rise that will deal with the escalating cost of living crisis.

“There will be significant disruption on August 19 but TfL and Arriva Rail London bear responsibility for this break down in industrial relations.”