The UK Government think-tank Commission for Integrated Transport is currently considering a plan to impose a congestion charge on flights. It warns that the number of flights is growing by five per cent annually from the present figure of 162 million a year. Ten years ago, planes caused 3.5 per cent of man-made greenhouse gases in the world. By 2050, this figure is estimated to rise to 15 per cent.

The toll, to be introduced on flights leaving at the most popular times, could double the amount travellers pay in the UK on departure tax, which currently stands at between £5 and £40. The charge is being considered to raise an extra £600 million to offset the damage aircraft is causing to the environment.

Airlines in Britain already pay £800 million to offset the damage they cause. The commission says they should be paying £1.4 billion for congestion charges on mid-morning or early evening flights. UK airlines have dismissed the proposal, saying passengers were already taxed enough. British Airways said: 'The way to relieve congestion is to meet demand and that means extra runways.' Holiday operator Thomas Cook added: 'Passengers are already being taxed enough.'