EDF Energy, the company behind the project, said it was pushing back the date for generation to start to June 2027.

It estimated the projected cost would now be in the range of £25bn-£26bn.

The France-based company blamed further effects of the COVID pandemic, arguing it had severely constrained people, resources and supply chains.

It highlighted limits to the number of people allowed on site during the height of the public health emergency.

It did not rule out further delay.

The Somerset plant was originally supposed to have started producing electricity - enough to power 7% of the country's needs - from 2017 at a cost of £18bn but it has endured years of headwinds.

EDF last updated its Hinkley Point construction schedule in January last year, when it said the plant would be postponed by six months to June 2026 with the cost rising by an additional £500m.

"The risk of further delay of the two units is assessed at 15 months, assuming the absence of a new pandemic wave and no additional effects of the war in Ukraine," the company said in a statement.

"In addition, the quantities of materials and engineering as well as the cost of such activities, including, in particular marine works have risen," the company said.

However, it said there would be no impact for UK consumers in terms of prices when generation finally begins.

New nuclear forms part of the energy mix the government wants as it seeks to bolster energy security in the wake of Russia's invasion of Ukraine that has placed severe strain on oil and gas prices.

The recent energy security strategy aims to target 95% of power generation from low carbon by 2030.

EDF's update represents a setback to that ambition.

The company is also battling problems in its domestic market as output from its reactors in France is hampered by corrosion problems.

EDF has warned they will take several years to repair, hampering French government plans to make France achieve carbon neutrality by 2050.