The Government plans to spend millions funding projects in developing countries. Last month, the Department for Environment, Food and Rural Affairs (DEFRA) agreed a £3 million deal with EEA Fund Management, a leading environmental investment manager, to reduce methane emissions, which are 21 times more damaging than carbon dioxide, in other countries. It hopes that projects in countries such as Thailand and China will help to "off-set the carbon footprint" caused by British ministers and officials who take to the skies.

The news has been welcomed by workers at Siam Products, a huge processing factory in Kalasin, North-East Thailand. For years, they have been subjected to the stench of waste water in which rotting vegetables are kept in ponds as part of a process turning cassava into starch for food and pharmaceuticals. Under the EEA scheme, this waste water and vegetables will be put into large holes from which foul-smelling methane is to be siphoned off and converted into electricity for use in the factory.

The Government has estimated that it will be responsible for 300,000 tons of carbon dioxide over the next 3 years. According to methodology used by Climate Care, a leading carbon off-setting company, this means that British ministers and civil servants are expected to fly more than 600 million miles every year.

To reduce this substantial "carbon footprint", the Government created a carbon off-setting fund last April. This obliged every branch of the Civil Service to fund schemes like the one in Kalasin, based on the amount of carbon dioxide each department produces when flying on foreign trips. EEA won the tender in December.

A spokesman for Friends of the Earth said: "Carbon offsetting is being promoted as an excuse to carry on flying."

Emily Armistead, the climate change campaigner for Greenpeace, said: "This is typical of the Government fiddling around the edges instead of making the cuts in emissions necessary to prevent climate disaster. It should find new ways of doing business that are far more environmentally friendly than flying."

Matthew Elliott, the chief executive of the Taxpayers' Alliance, said: "Taxpayers are already paying for civil servants and ministers to travel widely, often in business- and first-class. It is disgraceful that hard-pressed taxpayers should pay twice for their travel. If the individuals travelling really wants to offset their carbon footprints they should pay for it themselves. It is not up to taxpayers to do so."

However, Simon Shaw, the managing director of EEA, said: "The British Government is not only reducing global green-house gas emissions, and therefore its own carbon footprint, it also lessens the people of Kalasin's dependence on imported energy, and creates jobs in the local community."

Last year, Tony Blair ordered two customised aircraft to be used solely by prime ministers, the Cabinet and the Queen. The Government spent £6.1MILLION on ministerial travel overseas in 2005/06, a third of which is attributed to Mr Blair and which is a 20% increase year-on-year. DEFRA alone lavished £4. MILLION on trips abroad for its employees, a 25% increase on the previous year.

In 2005, the Department for International Development spent £900,000 on air travel within the UK alone and a further £8.3million on flights abroad. Many of these civil servants travelled business- or first-class.