Toshiba Westinghouse, owner of Springfields, is in the running to build the reactor for the UK's new-build nuclear power station.

But the Health and Safety Executive has not yet started examining the company's designs because of safety concerns around another firm's proposals.

Rival bidder, French company Areva and EDF, has received confirmation from the Nuclear Installations Inspectorate (NII) of concerns about the technology being used for the four reactors it wants to build across the country.

And the Health and Safety Executive, which oversees the NII, said the design could be rejected for use in the UK if its concerns could not be addressed.

Fylde MP Michael Jack said the news could be bad for Westinghouse as it could delay the firm's proposals being examined.

It could also cause problems if Springfield's AP1000 reactor followed similar designs to its rivals.

He added: "I have written to the NII expressing my concerns. It is proposed the reactors will be online by 2018 but this news could put back various bidders and this could well be bad news for the workforce on the Fylde.

"It is important designs suit the needs of the NII and I am hopeful Toshiba Westinghouse has taken this into consideration."

Areva and EDF is in talks with the NII about a revised design.

There are 10 AP1000 reactors in service around the world – with four in China and six in the US.

It is proposed to use the new reactor at eight further nuclear plants, in the United States.

A spokesman for Springfields said: "Westinghouse believes the AP1000 reactor is ideally suited for the worldwide nuclear power marketplace.

"The AP1000 has already gained certification in the USA from regulatory body, the Nuclear Regulatory Commission (NRC), and we are confident the reactor, which features the most advanced instrumentation and control in the industry, will satisfy safety requirements of UK regulators."

Areas that have been successful in the bidding process for the UK's new nuclear power stations include Wylfa Peninsula in Anglesey, Oldbury in Gloucestershire and Bradwell in Essex.

In the UK, Westinghouse runs the Springfields site at Salwick, which employs more than 1,500 people, hundreds of them from the Fylde coast, on behalf of the Nuclear Decommissioning Authority.

The vast majority of the UK's nuclear fuel has been made at Springfield over the past 50 years.