UK’s public spending watchdog to investigate Lower Thames Crossing project

The UK’s public spending watchdog has said it plans to investigate the Lower Thames Crossing, as campaigners voice concerns over the rising costs of one of the UK’s largest infrastructure projects.

The head of the National Audit Office (NAO) said he anticipated the agency would “examine and report” on the planned £11bn road tunnel between Kent and Essex, and that work to monitor the project had already started.

In a letter to campaigners opposed to the project who have been calling for an investigation, the NAO’s head, Gareth Davies, said: “I anticipate that I will examine and report on the Lower Thames Crossing. My teams are tracking activity on the programme. This will inform my decision on the right timing for audit work.”

Ministers committed this month to plough ahead with the controversial and long-delayed project, after it was spared from billions of pounds in cuts to infrastructure projects earmarked by Keir Starmer to help make way for a £15bn increase in defence spending.

It emerged last month that £174m of additional public money was being made available for the scheme, which is estimated to cost more per mile than the HS2 high-speed rail link from London to Birmingham.

The government has committed £3.1bn to the construction of the twin 2.6-mile tunnel, which is designed to ease congestion on the Dartford Crossing, with the rest of the project expected to be financed by the private sector.

With more than £1bn spent before any building work starts, Labour ministers frustrated with Britain’s sclerotic handling of large infrastructure projects say the scheme exemplifies why planning reform is needed urgently.

The Guardian revealed last year that the DfT had taken direct control of the Lower Thames Crossing project, forcing National Highways to relinquish its role as the main agency involved in planning and oversight.

A licence to run the new tunnel and the existing Dartford tunnel about seven miles to the west is expected to be handed to a private consortium in 2029, offered in perpetuity and overseen by a regulator. The completion date for works is now scheduled for 2034.

However, campaigners at the Transport Action Network (TAN) are hoping the arrival of Andy Burnham as prime minister could lead to a rethink over the use of public funds to help build a privately run asset.

Against a backdrop of mounting costs and concerns over carbon emissions, the campaign group, which helps communities to push for better and more sustainable transport, wrote to the NAO earlier this year calling for an investigation.

In April, Davies replied that no work was under way but that he would “keep this topic in mind”. However, his latest letter replying to TAN, dated 6 July, suggests the watchdog is moving closer to taking action.

“When we start new work we publish work-in-progress notices on our website. This provides an opportunity for interested parties to be in touch with the teams working on the studies. At the point at which we begin any work on Lower Thames Crossing I will ask my team to contact you,” Davies wrote.

Abby Coften, the TAN chief executive, said: “We’re pleased the NAO agrees with us that the privatised Lower Thames Crossing (LTC) needs investigating. However, this must be fast-tracked before more public funds are wasted. The same mistakes are being made as on HS2, but worse as LTC costs more per mile and has no completed business case.

“Billions of pounds of taxpayers’ money are being spent for just five years’ relief at Dartford. Meanwhile the toll revenues at LTC and Dartford will be gifted to private investors, and lost to the exchequer. It’s time to give the LTC the red card.”

An NAO spokesperson said: “The Lower Thames Crossing is a significant programme and is of high parliamentary and public interest. The NAO is tracking activity on the programme, which will inform its decision on the right timing for audit work. A work in progress notice will be published on the NAO website once work has begun.”

A spokesperson for the Department for Transport, said: “The NAO routinely reports on major government investments, and we would expect the same to apply to the Lower Thames Crossing.

“The cost-per-mile comparison to HS2 is misleading - these are entirely different projects with different objectives. Doing nothing at Dartford is simply not an option. Creating a new connection will reduce congestion, boost economic growth and establish a new strategic trade route between the ports of the South East, the Midlands and the North.”