The UK tax system is failing to address the cost of the emissions, air pollution and safety concerns of large luxury cars, which is causing their proliferation on British roads, green campaigners Transport & Environment (T&E) have found.

The body said that current legislation could see the UK become “a tax haven” for car manufacturers keen to sell larger cars.

Previous T&E research found that cars in the UK are getting so big for British roads that many now exceed the 180cm minimum for on-street parking. On average, cars were widening by 1cm every two years.

An analysis of the tax systems of countries across the EU and the UK found that the gap in tax paid in the UK between battery electric SUVs and petrol SUVs ranks 24th out of 31 European countries.

This is largely down to the UK’s comparatively low acquisition tax (first-year vehicle excise duty – VED), meaning high-polluting cars are taxed at a significantly lower rate than other European countries.

For example, a medium...