Every member of the Cabinet offered a gas-guzzling Jaguar worth £50,000

Every Cabinet minister is to be offered a brand new Jaguar XJ limousine worth at least £50,000.

The upgrade is being justified on security grounds, but was attacked by Conservative Shadow transport secretary Chris Grayling last night as "the act of a government that has been in power too long".

Currently only the most senior ministers such as John Prescott are entitled to a Jaguar model as their official car. The rest make do with much cheaper Vauxhalls and Rovers.

But details of an overhaul of the ministerial fleet prompted by the demise of the Rover marque emerged in a report in The Mail on Sunday. The newspaper reported a Department for Transport spokesman saying: "The cars available to ministers have been subject to review by the Government Car and Dispatch Agency because current cars are no longer in production.

"In future all Cabinet ministers will be given the choice of a British-built biodiesel Jaguar or a hybrid vehicle. Because of security considerations there has to be an option for a more powerful car than a hybrid."

Although the new Jags are the "greenest" in their class they cannot compete with the hybrid model being offered, the Toyota Prius, for environmental impact.

The Jaguar V6 Diesel has a top speed of 141mph but it does only 35 miles to the gallon. Cabinet ministers with an eye to their green credentials may opt instead for the Prius, less than half the price, with a top speed of just 106mph but an impressive 65mpg.