The Enquirer understands that the two main bidders led by Laing O’Rourke and Balfour Beatty had the delay confirmed this morning.

Both firms were expecting a winner to be chosen next week.

But the election of new French President Francois Hollande has prompted a fresh look at the project as he promises to cut back on nuclear power. EDF is 83% owned by the French state.

A source close to the project told the Enquirer: “The French election has muddied the waters a bit and EDF have said they are delaying an announcement while things are settling down.

“We are only expecting a few weeks delay and everyone is fully committed to the project.”

A Kier Bam joint venture was awarded the £100m site preparation contract at Hinkley last year but main work has still not started.

The Enquirer understands that the joint venture is now looking at next spring as the earliest start day for work to get going at the site and resources are being deployed to other contracts.