The framework will be split into two lots.

The first is for a single partner acting as a principal contractor taking on management and co-ordination of the packaging of ground investigation works as well as the planning and implementation of GI site enabling works across the phase two route.

The second lot is to establish a panel of 10 ground investigation contractors, which will deliver an estimated £215m programme of works.

Partners will capture geotechnical, hydrogeological and geo-environmental data through surveys, the excavation and detailed logging of exploratory holes, and in-situ and laboratory testing, culminating in the production of factual reports across the phase 2 route, some land of which will be in areas of historic mining.

Firms have until 19 August to submit bids with winner named in September 2022.