The UK Government has committed £800 million towards the delivery of the Lower Thames Crossing, a landmark infrastructure project that will include twin 4.16 km tunnel drives beneath the River Thames. Once complete, they will be the longest bored road tunnels in the United Kingdom.
The scheme is designed to provide much-needed relief to the overburdened Dartford Crossing by offering an alternative connection between Kent and Essex. This will improve resilience on one of the country’s most important transport corridors.
Government approval was secured in 2025, with construction expected to begin in 2026 and completion anticipated by 2032. The project involves several major contracts, including a joint venture between Bouygues and J. Murphy & Sons for the tunnelling works, Balfour Beatty for the northern approach roads, and Skanska for the Kent road connections.
One of the key innovations in the tunnelling process will be the reuse of a single tunnel boring machine for both bores. This method is expected to save significant time and cost in comparison with conventional twin-TBM deployment.
The Lower Thames Crossing is projected to transform connectivity in the South East, reducing journey times and creating economic growth opportunities across the region.
By committing public funding alongside private financing, the government has reinforced the importance of this project as a national priority.
The scheme is widely considered one of the most technically ambitious infrastructure projects in the UK today, with the tunnels expected to set a new benchmark in design and delivery.