The government has given the go-ahead for the construction of the UK’s longest road tunnel, as part of a £9bn infrastructure project aimed at easing congestion in the South East. The Lower Thames Crossing will connect Tilbury in Essex with Gravesend in Kent, featuring twin tunnels running beneath the River Thames to reduce pressure on the Dartford Crossing by an estimated 20%.

Spanning 14.5 miles (23km), the route will link the A2 and M2 in Kent with the A13 and M25 in Thurrock. Of the total route, 2.6 miles (4.2km) will be underground. Construction is expected to start in 2026, with completion targeted for 2032. The scheme, first proposed in 2009, has already cost over £1.2bn in planning and consultations.

Dartford MP Jim Dickson hailed the announcement as long overdue, calling it a solution to the “gridlock” suffered daily by local residents. However, not everyone is convinced. Environmental groups and local campaigners have voiced serious concerns about the project’s ecological impact, especially on ancient woodland and greenbelt areas.

While the full funding model remains undecided, the government confirmed that public investment will support early utility works, with private finance expected to play a major role. National Highways has described the development as a transformative step towards safer, more efficient road travel.