spiralling costs and secrecy have all the hallmarks of HS2
Beneath the Thames, a tunnel is taking shape — and so is a familiar story. The British government has quietly added another £174 million to the Lower Thames Crossing, bringing public commitment to £3.1 billion on a project whose per-mile cost already exceeds that of HS2. The scheme, designed to ease one of Europe's most congested motorways, will ultimately be handed to a private consortium to operate in perpetuity — yet no published business case has been offered to justify the public's growing stake in it. In the space between infrastructure necessity and institutional opacity, the same questions that haunted HS2 are beginning to surface again.
- Costs are climbing faster than comparable schemes — the tunnel already costs more per mile than HS2, a project that became a byword for runaway public spending.
- A third major funding injection in under a year contradicts the chancellor's own assurance that a previous tranche would be 'the final' one.
- Critics accuse the Department for Transport of quietly raiding the National Highways budget rather than seeking fresh parliamentary approval, bypassing normal democratic scrutiny.
- The government has yet to publish an outline business case — the standard document that would allow the public to assess whether the project's assumptions hold up.
- A private consortium is set to take over operations in 2029, running both the new tunnel and the existing Dartford crossing under a perpetual licence, with tolls regulated but guaranteed.
- Campaigners warn the pattern — escalating costs, privatised operation, withheld justification — mirrors the early trajectory of infrastructure projects that later unravelled.
The government has quietly committed a further £174 million to the Lower Thames Crossing, a road tunnel planned to run beneath the river between Kent and Essex. Drawn from existing budgets rather than new allocations, the funding brings total public investment to £3.1 billion — ahead of an expected £7.5 billion contribution from a private consortium. The move has reignited anxiety about a project whose costs are already climbing at a rate that exceeds HS2 per mile.
The tunnel is intended to relieve pressure on the M25, one of Britain's most congested motorways, and carries an estimated total price tag of £11 billion. The Department for Transport took direct control of the project last year, removing National Highways from its lead role. This latest £174 million represents the third significant funding injection in less than a year — following £590 million in the 2025 spending review and £891 million in the autumn budget, which Chancellor Rachel Reeves described at the time as 'the final tranche of government support.'
What has drawn the sharpest criticism is not the spending itself but the absence of an outline business case — the standard document that precedes major public works and allows independent scrutiny of a project's financial logic. The private consortium set to operate the tunnel, along with the existing Dartford crossing, will hold a licence in perpetuity under regulatory oversight. Construction is scheduled for completion in 2034, with private operation beginning in 2029.
Rebecca Lush of the Transport Action Network accused the department of siphoning money from the broader National Highways budget to sustain a project 'quickly running out of control,' drawing an explicit parallel to HS2. She noted the particular irony of a government nationalising the railways while quietly privatising the roads. The Department for Transport defended the allocation as vital to national infrastructure and said tolls would be independently regulated — but did not address the missing business case or the decision to allocate funds without a fresh parliamentary announcement.
The Lower Thames Crossing now occupies an uncomfortable position: substantial public money committed, private operation assured, and a studied reluctance to publish the analysis that would normally justify both. Whether it follows the trajectory of the projects it increasingly resembles remains an open question.
The government has quietly committed another £174 million to the Lower Thames Crossing, a road tunnel planned to run beneath the Thames between Kent and Essex. The additional funding, drawn from existing budgets rather than new allocations, brings the total public investment in the project to £3.1 billion—before a private consortium is expected to inject a further £7.5 billion. The move has reignited concerns about a project whose costs are already climbing faster than comparable infrastructure schemes.
The Lower Thames Crossing is envisioned as a new route to relieve congestion on the M25, one of Britain's most heavily trafficked motorways. The tunnel itself carries an estimated price tag of £11 billion. What has alarmed observers is the per-mile cost: the project is already more expensive per mile than HS2, the high-speed rail link from London to Birmingham, a scheme that has itself become synonymous with budget overruns and political controversy. The Department for Transport took direct control of the project last year, removing National Highways from its lead role in planning and oversight.
The £174 million announced in March will fund public works on both sides of the tunnel entrance. It represents the third major funding injection in less than a year. The government allocated £590 million in the 2025 spending review, followed by £891 million in the autumn budget—which the chancellor, Rachel Reeves, described at the time as "the final tranche of government support." That characterization now appears premature. Transport Secretary Heidi Alexander and the chancellor have both emphasized the project's importance to the country's infrastructure needs.
Yet the government has not published an outline business case for the scheme, the standard review document that typically precedes large-scale public works. This absence has become a focal point for critics. The private consortium expected to operate the tunnel—along with the existing Dartford crossing seven miles to the west—will receive a licence in perpetuity, overseen by a regulator. Construction is now scheduled to finish in 2034, with the private operator taking over in 2029.
Campaigners have seized on the funding pattern and the lack of transparency. Rebecca Lush, a roads campaigner at the Transport Action Network, accused the Department for Transport of siphoning money from the broader National Highways budget to prop up a project "quickly running out of control." She drew a direct parallel to HS2, noting that the Lower Thames Crossing already costs more per mile than the rail scheme, yet the government has refused to release the business case that would allow public scrutiny of the project's assumptions and justifications. The irony, she pointed out, is sharp: the government is nationalizing the railways while privatizing the roads.
A Department for Transport spokesperson defended the allocation, calling the tunnel a vital infrastructure project and noting that £3.1 billion has been committed to date, including the £891 million to complete publicly funded works needed to attract private investment. On the question of tolls—which will almost certainly be charged to users—the department said any charges would be regulated by an independent regulator to keep prices fair. The spokesperson did not address the absence of a published business case or the decision to allocate additional funds without a fresh parliamentary announcement.
The Lower Thames Crossing now sits at a peculiar juncture. The government has committed substantial public money and political capital to its completion by 2034. Private investors are expected to fund the majority of construction and then operate the facility for decades. Yet the public has not been given the detailed financial analysis that would normally justify such a commitment. The pattern—escalating costs, funding drawn from existing budgets, private operation of what was once public infrastructure, and a studied reluctance to publish justifying documents—echoes the trajectory of other major projects that have disappointed. Whether the Lower Thames Crossing will follow the same path remains to be seen.
Citações Notáveis
The spiralling costs and secrecy have all the hallmarks of HS2, with LTC already costing more per mile than HS2.— Rebecca Lush, Transport Action Network
The final tranche of government support to enable the private sector to take forward construction and long-term operation.— Chancellor Rachel Reeves, describing the autumn budget allocation (now contradicted by the additional £174m)
A Conversa do Hearth Outra perspectiva sobre a história
Why is the government adding more money to this project if it already said the autumn budget was the final tranche?
Because the costs keep growing, and they need to keep feeding it. The £891 million was supposed to be enough to unlock private investment, but infrastructure projects rarely work that way. Once you've committed politically, you keep finding reasons to add more.
What's the significance of not publishing a business case?
It's the document that would show the public whether this project makes sense—whether the benefits justify the costs, what the assumptions are, what could go wrong. Without it, there's no independent way to judge whether £11 billion is reasonable or whether this is another HS2 in the making.
The article mentions HS2 several times. Why keep comparing them?
Because HS2 is the cautionary tale everyone knows. It started at one price, ballooned to another, faced constant delays, and became a symbol of government infrastructure gone wrong. The Lower Thames Crossing is already more expensive per mile, and it's following the same pattern—more money, less transparency, private operation of what should be public.
So who actually benefits from this arrangement?
The private consortium that wins the contract benefits enormously. They get to operate a toll road for decades, collecting revenue from drivers with no real competition. The government gets to say it's building infrastructure without fully funding it. Drivers get a new route, but they'll pay tolls to use it.
Is there any chance this gets cancelled?
Unlikely at this point. Too much political capital has been spent. But the lack of a business case means the public is essentially being asked to trust the government's judgment without evidence. That's a harder sell each time the costs rise.