Two giant tunnelling machines will excavate the final 4.5 miles of HS2's underground route into central London, marking a significant milestone for Britain's high-speed railway project.

Weighing 1,250 tonnes each, the tunnel boring machines (TBMs) named Karen and Madeleine will launch from Old Oak Common station, aiming to reach London Euston in approximately 18 months.

The machines, manufactured by Herrenknecht AG in Germany, feature a 8.53m cutterhead optimised for London clay.

They will excavate tunnels at an average speed of 16 metres per day, creating a 7.55m inner tunnel diameter.

Mark Wild, the new HS2 Ltd CEO, will oversee the project's transition from construction to operational railway.

Former CILT(UK) President and now Rail Minister, Lord Peter Hendy described the project as "once-in-a-generation", highlighting its potential to improve transport links and unlock economic growth.

Rail Minister, Lord Peter Hendy said: "HS2 will not only improve transport links for millions but unlock huge potential for growth, jobs and regeneration right across the country.”

Mayor of London Sadiq Khan welcomed the Government's commitment to complete the Euston terminus and said it will deliver “real benefits that will help to build a fairer and greener London for everyone and deliver the change Britain needs.”

The tunnelling project, led by the Skanska Costain STRABAG joint venture, is expected to begin boring in 2025.

The approach to Euston will be completed by spray concrete lined tunnels which will then transition into three tunnels, which will enable trains to be fed into and from platforms at Euston station.

Final plans for the future HS2 terminus station at Euston are still under review and HS2 Ltd is continuing to work with the Government and other stakeholders to design an affordable station design that can run HS2 services from London to the Midlands.

HS2 stated further details will be announced by the government in due course