The PRA has added its voice to protests after reports that the government is planning further tax penalties for diesel drivers.

PRA chairman Brian Madderson said: “The Petrol Retailers Association strongly agrees with the UK’s leading motoring and freight organisations, that the Chancellor’s first aim should be to support the economy in this crucial period ahead of our formal exit from the EU by cutting fuel duty. This is already among the highest in Europe, especially for diesel.”

He said the Government’s own data showed an irreversible trend decline in diesel volumes had already commenced with only 0.8% growth in the first half of 2017, compared with the same period in 2016 which was 4.2%. This was mirrored by the slump in both new and second hand diesel car sales.

Madderson added: “No further government intervention by way of a duty increase on diesel is warranted at this time. Any narrow political gains the Chancellor may reap by further penalising already hard-pressed diesel drivers in a desperate attempt to ‘go green’ will come at the expense of lost growth, fewer jobs and lower living standards.”

Responding to the reports, RAC chief engineer David Bizley warned the changes could increase the problem of pollution caused by older diesel engines.

He said: “We are concerned that those who drive long distances, business drivers especially, might consider sticking with their older diesels given the superior economy they offer. It would be a terrible misjudged ‘knee-jerk’ reaction which could backfire and have the unexpected effect of encouraging these owners of older diesels and fleets not to upgrade to newer, cleaner diesels which offer significant benefits in reduced emissions.

“This isn’t what the Government, or any of us, want and is the opposite of what is needed from an air quality perspective. However, it would also be grossly unfair to penalise owners of current diesel vehicles.

“The irony is that the next generation of diesel engines that manufacturers are developing right now are likely to be as clean as their petrol equivalents, so while a new tax might be logical in the short term, this logic will likely not apply within a year or so.”

AA president Edmund King suggested the Government should be incentivising alternative fuels rather than demonising diesel.

He said: “It is ridiculous to further demonise diesel via differential taxes when drivers are already voting with their wheels.

“Some 41% of AA members own diesels, but that drops to 16% when drivers are asked what fuel their next car will run on.

“Indeed in October diesel sales were already down 29.9% compared with last year. The Treasury should concentrate on incentives for greener cars rather than hitting diesel.”