Plans for a second runway at Gatwick Airport have been grounded until 2019 at the earliest.

Transport Secretary Alistair Darling is due to announce the Government's future strategy for air travel in the South-East in the next three weeks.

But while the consultation document will say extra carrying capacity is desperately needed to meet increasing demand, only one of four possible solutions will involve Gatwick, say Whitehall insiders.

This would first involve the construction of one new runway at Heathrow, one at Stansted, in Essex, followed by a new runway at Gatwick after 2019.

The news will come as a relief to campaigners who feared ministers had found a way around a local agreement which blocked a new runway at the airport for 40 years from 1979.

The remaining options are a new runway at Heathrow, two at Stansted and a new four-runway airport near the village of Cliffe, on the Thames Estuary in north Kent.

Earlier this year, it was claimed the Government had found a way round the agreement signed by West Sussex County Council and the British Airports Authority in 1979 which would prevent the building of a second runway until 2019.

It would increase the number of passengers through Gatwick each year from 30 million to between 80 and 100 million.

The 1979 deal was signed with BAA because of alarm sparked by proposals for a second Gatwick terminal.

Local residents believed a second terminal meant another runway.

BAA said a second runway was not in its plans and the agreement was drawn up to remove the issue from the public inquiry.

Last week, Transport Minister John Spellar made it clear that extra air capacity in the South-East 2019 is earliest date for runway was crucial. He said: "If we fail accurately to respond to capacity needs, Britain will lose out."

Firm proposals are expected to be published in the autumn.

Brendon Sewill, chairman of Gatwick Area Conservation Campaign, said: "Any new runway at Gatwick would be an environmental disaster and we will wait until the consultation paper is published before we relax any of our protests.

"The proposal was first made in 1952 and we are still totally opposed to it."

Mr Sewill said the best alternative would be to build a new airport along the coast where the noise pollution would be lost out to sea.

He said there was no room for a second runway at Gatwick and no room to accommodate the extra workers who would be needed during and after construction.

He said: "The main effect is it would require 45,000 new jobs for which there is no labour available.

"That would mean the equivalent of a new town the size of Crawley.

"It has been on the cards for the last 50 years and has always been put off because it has been found to be impractical when they look at it in detail.

"People like businessmen say let's put a new runway at Gatwick. The problem comes when you look at where to put it."