The government stands accused of breaking its own targets on traffic congestion and pollution after it was revealed that ministers and officials are being ferried around in a record number of chauffeur-driven cars.
The average engine size has also increased, despite official policy, outlined by Paul Boateng, chief secretary to the Treasury, to encourage private company car drivers "to move to smaller and cleaner cars" by putting higher car taxes on polluting vehicles.
According to figures released to Norman Baker, the Liberal Democrat environment spokesman, after a series of parliamentary questions the government's car fleet has grown by 20 in the past two years to 207. Of these around 81 are dedicated to ministers, an increase of around four since Labour took power.
The biggest rise followed a conscious decision to develop the ministerial and officials car pool. This has allowed many more officials and junior ministers to call up cars at short notice rather than use public transport.
The government has upgraded 15 armoured luxury limousines in response to the increased terrorist threat. Ministers are also being allowed to use luxury cars - including Jaguars - from private hire companies when they are on official business outside London.
The Whitehall agency responsible for ministerial cars has also ended its policy of publishing figures that show how many ministerial cars are environmentally friendly - despite a government campaign highlighting green vehicles
All four living former prime ministers - Lord Callaghan, Edward Heath, Lady Thatcher and John Major - have heavy armour-plated chauffeur-driven Daimlers for protection. These are the least environmentally friendly vehicles.
Other ex-ministers who have chauffeur-driven armoured cars include the former Northern Ireland secretary who introduced internment, Lord Mason of Barnsley, and a former Tory minister, now an independent MP for Basingstoke, Andrew Hunter.
John Prescott, the deputy prime minister, is the only cabinet minister to be allocated a Jaguar without armour plating. His cabinet colleague, Paul Murphy, the Northern Ireland secretary, has an armour plated Jaguar XJ6 with full police protection.
All other cabinet ministers either have a Rover 75, a Rover 800 or Sterling or a Vauxhall Omega. Sir Andrew Turnbull, the cabinet secretary, and all permanent secretaries, have a similar choice to cabinet ministers. Ministers of state can choose between a Ford Mondeo, a Vauxhall Vectra or a Nissan Primera.
Other top officials who have cars include Sir Liam Donaldson, the chief medical officer and Sir John Bourn, the comptroller and auditor general. The government car service has only one BMW - a 7 series - but one minister, Mike O'Brien, minister of state at the Foreign Office, is campaigning to get BMWs on the government-approved list - the engines are made in his North Warwickshire constituency.
"Ministers and senior civil servants are travelling around in expensive and bigger cars while at the same time the government is supposed to encouraging people not to drive and use public transport" said Mr Baker, in response to the written answer. "It would be much better if some of those government whips were given season tickets rather than able to jump into a ready pool of government cars."
Official figures show that the majority of cabinet ministers and permanent secretaries' cars - Vauxhall Omegas - are made in Germany.