Britain faces a rising risk of electricity rationing by the next general election unless ageing gas plants are replaced. A report by consultancy Watt-Logic warns urgent action is needed to secure reliable, low-carbon supply.

More than a dozen gas-fired stations built in the 1990s are nearing end of life, with no major refurbishment plans. Gas still supplies around one-third of UK electricity, rising to two-thirds on low-wind days.

Kathryn Porter, the report’s author, says many plants could be forced offline within five years. Long lead times for replacing worn components, such as rotors, increase the risk of sudden failures.

The challenge is compounded by nuclear closures, with eight of the UK’s 10 remaining reactors due to shut before or during 2030. The report says the highest risk window is between 2028 and 2031, when reliable capacity losses are expected to peak.

“Without urgent action to secure dispatchable generation and stabilise the gas network, the UK faces escalating risks of supply shortfalls and widespread system failures well before 2030,” the report warns. It adds that even maintaining current demand could become difficult without rationing.

Rising electricity use from electric vehicles, heat pumps and industrial electrification will further strain the system. Scotland faces added risk, relying on just two major stations to maintain grid stability.

Shadow energy secretary Claire Coutinho said the findings show net zero policy is harming the economy and called for a rethink. The National Energy System Operator disputes the warning, saying Britain has one of the world’s most secure systems.

A Government spokesperson said: “This report is nonsense scaremongering, as confirmed by the National Energy System Operator, who has been clear the faster we decarbonise, the more secure we are.”

Energy experts say the long-term solution is rapid investment in clean, firm power and storage. Without it, short-term reliance on ageing fossil assets could undermine both emissions targets and energy security.