Theresa May has given the go-ahead for the proposed ￡18bn nuclear power station at Hinkley Point in Somerset following a “revised agreement” with French company EDF, ending months of uncertainty over the fate of Europe’s biggest energy project.

The plans were unexpectedly put on hold in July to give the new UK prime minister time to assess concerns over its high cost, unproven technology and the role of Chinese investors in a plant that is expected to meet about 7 per cent of domestic electricity demand.

However, Mrs May has concluded that Hinkley is crucial to keeping Britain’s lights on and reducing carbon emissions as old power stations accounting for more than half the country’s existing generating capacity are phased out over the next 15 years.