Opponents of the third runway at Heathrow airport, who say the government's expansion plans are an environmental disaster, are putting forward alternative plans for a rail hub there.
The idea is being put together in detail by the 2M group, formed of 21 local councils representing 4 million residents.
Their £1.5 billion blueprint, Getting to Heathrow, shows how the number of trains passing through the airport could match the number of planes it currently accommodates.
There would be connections to 150 stations within a 25-mile radius of Heathrow. A new North-South high speed line would connect with Glasgow, Edinburgh, Birmingham, Manchester, Liverpool and Leeds.
The proposal coincides with the government's narrow success in getting the Heathrow expansion through its latest stage in the House of Commons. Their majority was slashed to just 19.
Twenty-nine Labour MPs rebelled against the government but more than 20 more were bought off by ancillary environmental promises - which opponents believe will be ditched or watered down when the new runway is built, and in any case do not go to the heart of their objections.
The alternative planners say it could take a million cars off the road every year.
"The Government's plans for a third runway include a £4.5bn high speed Heathrow hub,” said Wandsworth Council leader Edward Lister on behalf of 2M.
“This is nothing more than a high speed hoax as just about all the costs will be swallowed up by a 15-mile tunnel to St Pancras. Our scheme is practical and offers much better value for money.”