The two main bid teams led by Laing O’Rourke and Balfour Beatty met with energy giant EDF today for an update on the project.
But contractors fear delays in the contract award will give EDF the chance to squeeze margins on the job.
A winner for the £1.2bn civils package was due to be announced this month.
But bidders are not expecting a decision now until late summer at the earliest as uncertainty over the project continues in the wake of the election of new French President Francois Hollande.
Hollande has promised to cut back on nuclear power. EDF is 83% owned by the French state.
A source close to the project told the Enquirer: “Everything is being delayed now and there seems to be little urgency about awarding the contract.
“It’s such a massive job the client knows it can keep bidders hanging on.
“I’m sure they will use this extra time to compare the two bids and incorporate the best, or cheapest solutions, in the final win.
“The price is sure to get driven down while EDF demands the highest rates it can for energy produced by the plant.”
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.