The Heysham 1 plant in northwest England and the Hartlepool facility in the northeast will continue generating energy until March 2028, an increase of one year, main operator EDF said in a statement.

The French company's announcement was confirmed by its British partner Centrica following "positive inspections".

"A further year of operation for these two stations has the potential to power more than four million homes," said Mark Hartley, managing director of EDF's nuclear operations.

"It secures employment ... for more than 1,000 people who work at those sites, and it supports the UK's ambitions to have a clean, secure electricity supply," he added.

Centrica said the stations reduced fossil fuel needs, while "supporting the UK's ambitions to have a clean, secure energy supply".

There is no change to the expected closure in March 2030 of two other plants, Heysham 2 and Torness.

Britain's fifth nuclear plant, Sizewell B, could keep operating until 2055, EDF noted Tuesday.

The facilities will eventually be replaced by new nuclear power plants.

The UK government in July gave Sizewell C the final go-ahead after reaching a deal with investors, aiming to bolster net zero and energy security goals.

The plant is not expected to start generating electricity until the late 2030s.

EDF is involved in constructing Sizewell C and another new UK plant, Hinkley Point C.

The UK has refocused on shoring up nuclear power since the start of the war in Ukraine, in the name of energy security and faced with a fleet of ageing power stations.

Prime Minister Keir Starmer's government has also pledged by 2035 to reduce UK greenhouse gas emissions by 81 percent on 1990 levels, under plans to reach net zero by 2050.

The use of nuclear energy as an alternative to fossil fuels is highly controversial, however, with many environmental groups warning about safety risks and the disposal of nuclear waste.