Ministers have been urged to explain why they took hundreds of journeys on the Queen's Flight.
Ministers have taken hundreds of RAF flights
Tony Blair has flown in RAF jets 670 times, at a cost of £1.2m, since becoming prime minister in 1997.
Environment Secretary Margaret Beckett took 106 RAF flights between 2002 and December 2004 - many to East Midlands airport, near her home in Derbyshire.
Conservative transport spokesman Chris Grayling accused ministers of using the planes as a "private taxi service".
Government officials said it was cheaper than commercial airlines and stressed the flights were within the ministerial rules.
'Sense of abuse'
Conservative transport spokesman Chris Grayling said: "Most people will be astonished at the way ministers seem to be using the Queen's Flight as a private taxi service.
"Ministers, including Gordon Brown, have been using it for short hops to Brussels, Margaret Beckett has been using it to drop her home in the East Midlands and the prime minister has been taking it on holiday with him.
COST OF RAF FLIGHTS 2002-2004
Prime Minister Tony Blair - £467,000
Foreign Secretary Jack Straw - £538,000
Environment Secretary Margaret Beckett - £107,000
Chancellor Gordon Brown - £71,000
Deputy Prime Minister John Prescott - £6,000
Transport Secretary Alistair Darling - £4,000
"Of course ministers will always need to use official aircraft on occasions but these figures create the sense that the system is being abused."
The Liberal Democrats also demanded the reasons for each of the flights be published.
But a Downing Street spokesman said Conservative prime ministers Margaret Thatcher and John Major had always used RAF flights for their holidays.
"In fact, Tony Blair is the first prime minister in recent years to use commercial flights, having done so for his holidays since 2000, other than one occasion where security advice was to the contrary," he said.
The Department for the Environment, Food and Rural Affairs said many of Mrs Beckett's meetings in Brussels "often end at unpredictable hours in the middle of the night when there is no alternative transport available".
The spokesman added: "Returning to the UK immediately allows attendance at high level meetings early the next morning and represents savings on hotel accommodation."
The environment department spokesman added: "Conscious of the environmental impact of aviation, all ministerial flights during the EU presidency last year were carbon offset as were emissions from all other sources."
A breakdown of each minister's use of the aircraft - officially known as 32 (The Royal) Squadron - was published by the Ministry of Defence in response to a freedom of information request.
The MoD said the transporting the Royal Family and senior politicians was "very much a secondary role" of the squadron.
Its primary purpose was securely transporting military personnel on operations and was only available for other users if the armed forces did not need the aircraft, a spokesman said.