Lower Thames Crossing as a PPP | It makes sense for the UK Economy

LTC as a Public–Private Partnership (PPP) model the pro arguement and what the benefit can be to UKPLC

The UK Government has confirmed that the transformative Lower Thames Crossing (LTC) delivery is to be considered through a Public–Private Partnership (PPP) model, unlocking billions in private investment while protecting taxpayers and ensuring on-time delivery of one of the country’s most strategically important infrastructure projects - but is this the correct approach over central gevernment funding?

The £9–16 billion scheme—set to be the longest road tunnel in the UK—is a central pillar of Britain’s future transport strategy, aimed at easing congestion on the Dartford Crossing, boosting freight capacity, supporting levelling-up in the South East, and strengthening the resilience of the national road network.

With planning permission granted in March 2025, the decision to explore a PPP reflects the scale, complexity, and national significance of the LTC, and the government’s ambition to bring forward major infrastructure without overstretching public finances.

Unlocking Private Capital for Public Good

The PPP model, underpinned by a Regulated Asset Base (RAB) framework, will enable the private sector to fund and deliver the project while recovering its investment through long-term, regulated toll revenue.

Over £1.2 billion has already been invested in land acquisition, environmental design, and community engagement. The PPP model ensures this momentum is maintained, with main construction now expected to begin in 2026, as the givernment seeks to avoid another HS2 banana skin where it is repeatedly forced to backtrack on plans.

Delivering Value, Managing Risk

PPP delivery allows the government to transfer construction and operational risks to private sector partners, reducing exposure to cost overruns and delays—common risks on megaprojects of this scale.

This model has proven successful on similar infrastructure, such as the Thames Tideway Tunnel, where it supported cost certainty, regulatory oversight, and timely completion.

Under the LTC PPP, toll revenues collected over the asset’s lifespan will provide a predictable return to investors while giving users a reliable, efficient, and high-capacity new crossing beneath the Thames.

Economic Growth and Connectivity

The Lower Thames Crossing is forecast to deliver:

• £40 billion in economic benefits over its lifetime

• 20 minutes saved per journey during peak times

• Up to 22,000 jobs supported during construction

• Enhanced freight capacity for up to 155,000 vehicles per day by 2035

• Significant congestion relief on the overburdened Dartford Crossing

  
  

Sustainable and Community-Focused Delivery

As part of the PPP framework, the government would mandate that contractors meet stringent environmental and social value requirements, including:

• Carbon-neutral construction targets - which have been built i nto all tenders

• Significant biodiversity net gain across the corridor

• Local job creation and apprenticeships - a part of National Highways commitments.

• Smart technology for real-time traffic management and safety

  
  

These requirements will be embedded in procurement contracts, ensuring that private investment aligns with the government’s Net Zero, skills, and levelling-up agendas.

Fiscal Responsibility at the Heart of Delivery

While the Regulated Asset Base model introduces additional long-term financing costs—estimated at £200 million above direct public funding—it allows the government to spread costs over time while accelerating delivery today.

A Model for Future Megaprojects

The Lower Thames Crossing PPP potentially could set a precedent for how the UK can deliver high-impact infrastructure in the coming decades. It balances ambition with fiscal discipline and combines public interest with private sector efficiency.

As the UK moves to strengthen economic resilience and connectivity, the LTC stands as a flagship example of how partnership models can turn strategic infrastructure into reality—on time, on budget, and for the benefit of generations to come.