Open Skies treaty

Talks towards "open skies" have been motivated by a desire to throw open routes in America and Europe to foreign airlines. The draft Open Skies treaty currently being negotiated by the US and EU is however, alarming environmental groups.

The treaty contains a clause inserted by the USA. Article 14 covers any environmental measures, which could have "possible adverse effects" on the free traffic of aircraft. Those countries that sign up to the treaty must "recognise that the costs and benefits of measures to protect the environment must be carefully weighed". The clause also states that disagreements between countries must be referred to a committee comprising governments, airports and airlines.

In its current form the treaty would curtail Britain's ability to impose green taxes on aviation fuel or a general tax on air travel.

Transport secretary, Alistair Darling, is understood to want the environmental article changed. Last year UK aviation emissions rose by 12% during 2005 and now account for about 11% of Britain's total greenhouse gas emissions.