Eurotunnel, the operator of the Channel Tunnel, has halted its UK projects, claiming “unsustainable” levels of taxation has made any future investments “non-viable”.

The company said it had been informed its business rates would increase by some 200% from next year.

It hit out at the government, arguing that the higher costs were “clearly contrary” to ambitions of growing the economy and increasing investment.

The Treasury said it would support firms “hit hardest” by tax hikes and would continue talks with affected industries over such concerns.

The outburst from Eurotunnel comes days ahead of next week’s Autumn Budget, where Chancellor Rachel Reeves will set out the government’s tax and spending plans.

Speaking to the BBC, Eurotunnel’s chief executive Yann Leriche said: “All our investments, all our plans are becoming unsustainable.

“As you know, business rates, it’s a property tax. And our property – the Channel Tunnel – has not changed. It’s still the same tunnel, the same terminal, the same trains. Everything is equal.

“And so to face such an increase… is a real issue for us. Because we know in rail, we invest for the long term.”

The potential 200% increase in business rates for Eurotunnel is a result of new calculations by the Valuation Office Agency (VOA), which provides the government with valuations and property advice used in setting taxation and benefits.

Mr Leriche said while discussions were ongoing, this could see its business rates rising from £22m to £65m.

A spokesperson for Eurotunnel said such a hike in business rates, along with other taxes, could put its total tax level at about 75% on UK earnings.

The VOA told the BBC the body “does not determine business rates” and that “next year’s liability has not yet been confirmed”.

“This unparalleled and unsustainable level of taxation makes any future investment in the UK non-viable,” the Channel Tunnel said.

“It is therefore impossible to develop new services, create jobs, and pursue what is needed for the long-term development of our activities.”

The company claimed it had “no other choice but to freeze our future investments in railway assets in the UK, starting in 2026”.

The BBC has asked Eurotunnel what investments it has frozen. The Financial Times reported that its chief executive, Yann Leriche, told the newspaper it had scrapped plans to reopen a freight terminal in Barking and to run a new direct freight service from Lille.

The Channel Tunnel is an undersea tunnel linking southern England and northern France. Nicknamed “Chunnel”, it comprises three tunnels, two rail tunnels used for freight and passenger trains, and a service tunnel.

The link between Folkestone and Calais is operated by Eurotunnel.

Separate company Eurostar, Eurotunnel’s biggest customer, operates passenger services through the tunnel between London and a number of other European cities on the continent, including Paris, Brussels and Amsterdam.

A VOA spokesperson told the BBC it had engaged with Eurotunnel and their advisers “on multiple occasions over the past eighteen months to discuss their valuation and fully explain our approach”.

“These discussions remain ongoing, and we are committed to continuing constructive engagement.”

The spokesperson added Eurotunnel could formally challenge the valuation.

Ahead of the Budget, the Eurotunnel called on the government to “provide certainty on business rates”.

The firm has not been alone in issuing warnings to the chancellor, with supermarket bosses claiming part of the government’s business rates reforms posed a problem for its industry.

Business rates are a tax on non-domestic properties such as shops, pubs and offices.

It is expected that Reeves will confirm the rates businesses will have to pay at in the Budget, along with further details, which will come into force in April 2026.

The Treasury said in response to Eurotunnel’s comments that it did not comment on “speculation around future changes to tax policy”.

It said once it understood the “complete” revaluation picture, it would be in a position to “make final decisions” on support.