It is the second extra payment since July when the three-way joint venture secured £300m in extra funding for planned and agreed changes to the scope of works.

Skanska’s share of the total contract sum is now valued at around £1.4bn, up from £1.12bn when the contract was signed in April 2020,

The JV is split by 34% Skanska, 34% Costain and 32% Strabag. When the JV contract was first awarded it was valued at around £3.3bn and is now up to around £4.1bn.

Since being given notice to proceed by HS2 in April 2020, SCS has been making significant progress amid inflationary cost pressures.

Two tunnel boring machines started operations in late 2022 from West Ruislip Portal towards Green Park Way – to date completing around 2.9km of their 8km journey.

Two further TBMs have been received in the UK and will be launched early in the next year from Victoria Road Crossover Box.

A third TBM is in operation from Atlas Road, constructing a logistics tunnel between Old Oak Common station site and the Atlas Road site.

The SCS JV said that preparation works were well underway for the launch of the two final TBMs from the Old Oak Common Box towards Euston, still due to begin in 2024 despite uncertainty about the Euston terminus plan which is being stalled to find a private sector funding partner.