Revised tenders for Google’s King’s Cross HQ contract are not due to be submitted to the internet giant until the New Year.

The Enquirer understands that contractors bidding for the job are working to a January 2015 deadline to submit new tenders.

The value of the contract has also doubled to £600m as Google radically alters the designs for its new UK flagship.

BAM Construct were named preferred bidder on the original £300m contract last March.

The contract race was then re-opened  after Google instructed architects Allford Hall Monaghan Morris to rework the scheme.

The re-bidding means original rival bidders Carillion and Skanska are back in the race with BAM.

Bidders are now looking at the New Year for the race to begin as the construction timetable is delayed while Google decides on designs and even the possibility of occupying a different plot on the King’s Cross site.

Work was due to start on site this year but design changes could add up to two years to the construction schedule.