The Enquirer understands the changes involve a number of sites in the North Chilterns area where EKFB (Eiffage, Kier, Ferrovial Construction and Bam Nuttall) was main contractor.

The Align joint venture of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick will take over the sites during the next six months.

A spokesperson for HS2 Ltd said: “In order to streamline the delivery of the central section of HS2 we are rebalancing some responsibilities between two of our main works contractors.

“This will allow us to capitalise on the capabilities that Align has built during the delivery of the Chiltern Tunnel, and allow EKFB to focus on the core section of the route that needs to be complete in order to start testing and commissioning.”