By politics.co.uk staff
The government spent £18.5 million on flights last year, casting doubt on its commitment to budgeting and reducing carbon emissions.
The Taxpayers' Alliance carried out the first Whitehall-wide report on flight spending, collating data for the 2008 period.
The report, which looked at 13 government departments' flight expenditure using the Freedom Of Information Act, also found the majority of tickets purchased were for first or business class.
£10.6 million was spent on first or business travel seats, more than half the total spent.
Ben Farrugia, a policy analyst at the TaxPayers' Alliance, said: "Departments need to be doing all they can to limit their expensive air travel.
"These figures show that too much is being spent on business class seats, and many departments are making unnecessary journeys abroad. With better management money could be saved. Flying should always be the last option, not the first."
Seven departments, including the Ministry of Defence, the Foreign Office and the Department of Transport, failed to provide information regarding their spending on flights.
The total bill for public sector flights, including quango's and other bodies is expected to be close to £70 million.
The Department of International Development was the biggest flyer, spending £6.8 million, with the Department of Work and Pensions coming in second by spending £3.3 million.
Data was previously collected by back-calculating from the government carbon offsetting statistics as earlier requests for the information were rebuffed.
Government spending on air travel has fallen since last year, when it stood at £20 million.