Close to 70 EDF staff are set to strike next week after talks to reach a deal between the company and its workers broke down.

The union Unite said its members will strike from Monday to Friday, including at EDF headquarters in Canning Town, because “pig-headed” bosses want to force Smart meter installation staff to work evenings and weekends.

EDF denied requesting its employees work hours outside of their contracts and said the company wanted only to improve services for customers and make operations more affordable.

A strike late last year was suspended after talks arbitrated by the conciliation service Acas.

Unite regional officer Onay Kasab said: ““Unite went into the Acas talks before Christmas in good faith, but they have been sabotaged by a pig-headed management.

“The main sticking point is the requirement to work regular evenings and weekends as part of the installation of the Smart meter programme. We had an agreement that current staff would not have their working hours altered – the employer has now reneged on this.”

Mr Kasab also said workers rejected a “telematics” system designed to record “every movement of an employee’s working day,” which he claimed would be used for bullying.

A spokesman for EDF, meanwhile, expressed disappointment that talks broke down – and stressed the company’s commitment to its customers.

“Our current proposals are fair, competitive and consistent with the commitment to our customers to ensure that we provide the services they require and that our costs are controlled and our services are affordable,” he said.

“Our employees are not being asked to work hours outside of those stated in their contracts. The changes will enable us to improve the service we are able to offer to customers and also improve the safety of our operations.

“We remain open, as always, to meeting employee representatives.”

Unite said its members voted by a margin of 85 per cent for strike action and 92pc were in favour of industrial action short of a strike.