NUGEN is declining to comment on reports that it is close to signing a deal with a South Korean energy giant to invest in a nuclear power station at Moorside, Sellafield.

NuGen, a partnership between Toshiba of Japan and the French company ENGIE, wants to build three Westinghouse AP1000 reactors at Moorside.

The News & Star reported in May that it had approached Korea Electric Power Corporation (Kepco) as a potential investor in the project.

Now The Financial Times is saying that Kepco is "closing in" on a multi-billion pound investment in Moorside.

NuGen is due to make a final decision on whether to proceed in 2018 with a view to starting construction two years later.

It is understood that Kepco held talks about joining the NuGen consortium in 2013, but no deal materialised.

NuGen has previously confirmed that it is talks with potential investors but declined to confirm on the latest Kepco speculation.

A spokesman said: “Our shareholders, Toshiba and ENGIE, remain committed to funding the development phase of NuGen’s Moorside project until a financial investment decision is reached [in 2018].

“It has always been part of our plans to include investors, debt and equity into the project.

"A universe of potential investment options is open to us and we have the flexibility to be able to talk with a wide range of potential investors.”

Moorside is seen as crucial to west Cumbria's prosperity. The three reactors would have a combined output of 3.6GW – enough to power 6m homes and supply 7.5 per cent of the UK's electricity needs.

The Government's surprise decision to delay a decision on the proposed Hinkley Point nuclear power plant in Somerset has cast a shadow over the Moorside scheme.

Ministers' concerns with Hinkley Point are understood to centre on the high price of the electricity it would generate, and Chinese involvement in the project.

But there is no Chinese investment in Moorside and NuGen chief executive Tom Samson has said that it hopes to agree a lower strike price for its electricity than that agreed at Hinkley Point.