The Campaign for Better Transport and Greenpeace have revealed that according to figures compiled by Transport for London, UK taxpayers could be asked to fork out £17 billion to cover the costs of transport needed to manage the massive surge in traffic a third runaway would require.
Commenting on the figures, Caroline Pidgeon said:
"These latest figures are a further confirmation that there is a gaping hole in the case for Heathrow expansion.
"This massive gap has been raised on a number of occasions by the London Transport Committee, which I have co-chaired since 2008.
"When I grilled Howard Davies, the Airport Commission's chairman, about his report last September he was in complete denial about the additional costs.
"The Davies report has now been totally discredited. The case against a third runway at Heathrow has never been stronger.
"It is time David Cameron stopped dithering on this issue and finally honoured his pledge of no ifs, no buts, no third Heathrow runway."