A former Treasury adviser is claiming Government policies on aviation will cancel out efforts to reduce greenhouse gas emissions.

Brendon Sewill, chairman of the Gatwick Area Conservation Campaign, said Britain's greenhouse gas emissions would be just as high in 15 years because of the Government's determination to have more air travel than ever before.

He is calling on Chancellor Gordon Brown to tax air travel in the way car travel is taxed.

He said: "The Government's targets on climate change are totally inconsistent. They propose reductions in industry while the aviation industry expands. The feeling in the country and in Europe is that the tax-free status of aviation cannot continue and that the projected rate of growth will seriously damage the climate."

The Department for Transport admitted the projected growth in aviation would cancel out reductions in greenhouse gases achieved by other industries by 2020 in its 2004 paper Aviation And Global Warming.

Mr Sewill said: "If aviation was taxed at the same rate as other forms of transport, it would have a dramatic effect on the growth of the industry and plans for second runways at Heathrow, Stansted and Gatwick would start to look very silly.

"The next time Gordon Brown has to put up taxes on something, aviation will be the obvious thing because at the moment it is virtually untaxed."

Earlier this year in a speech made to the Brussels think-tank, the Centre For European Policy Studies, Mike Clasper, chief executive of Gatwick Airport's owner the British Airports Authority, said there was a case for reducing the environmental impact of the aviation industry.

He said: "Across an increasing number of countries, work by academics, pressure groups, think tanks, political parties, legislators and governments has drawn attention to aviation's rising greenhouse gas emissions and all have concluded that something must be done about it.

"As a world citizen, I believe we have a responsibility to protect future generations from our actions today."