CAMPAIGN groups fighting airport expansion on behalf of the people of Hillingdon have dismissed the idea of an off-shore facility in Kent as 'unrealistic'.

Members of both HACAN and No Third Runway Action Group (NoTRAG) believe Heathrow will always remain the country's premier airport.

The groups were speaking in response to an announcement by Mayor of London Boris Johnson, who has launched a feasibility study into a four runway airport off the Isle of Sheppey, in the Thames Estuary.

Dubbed 'Boris Island' by one national newspaper, Mr Johnson said of his idea: "You can't endlessly expand Heathrow in the suburbs of west London and entrench what was really a planning error of decades ago.

"I'm looking at all the airports around the perimeter including the option of a new site somewhere in the Thames estuary, that's something I definitely think we should look at.

"What we are looking at is a way of solving this great capital's aviation needs without endlessly expanding our number one international airport."

However, John Stewart, chairman of HACAN, said: "We just don't think it is realistic to replace Heathrow. The market in the South East couldnÕt support two major hub airports.

"It would need to be either Heathrow or an off-shore airport. But who is going to invest in a new airport with Heathrow just the other side of London? The realistic way forward is to invest in high-speed rail in order to cut the number of short-haul flights using Heathrow."

Geraldine Nicholson, the Chairwoman of NoTRAG added: "We are totally against the expansion of Heathrow but we recognise the important part it plays in our local economy."