Skanska was fighting-it out with Balfour Beatty and Kier for the scheme but is now understood to have sealed the deal.

Construction information specialist Glenigan said the contract is due to be officially confirmed shortly.

The Defence Infrastructure Organisation said the “approvals process is still ongoing and no decision has yet been made.”

The MoD will close the existing RAF base at the end of this year and the plan is to convert the site into a major engineering training campus to develop skills in maintaining military equipment.

The £230m  project will involve demolition of existing building, essential infrastructure work, new buildings as well as refurbishment of existing facilities.

Defence Infrastructure Organisation’s current construction programme shows site mobilisation and enabling works in early 2014.

New build and refurbishment of existing buildings will start in spring 2014 and complete in winter 2015.