Exuberant costs incurred in transforming one of the busiest motorways in London to make way for a third runway could derail Heathrow expansion, it has been claimed.
That was the stark warning made by the boss of British Airways ' parent company, IAG, Willie Walsh.
On top of the "inflated £17 billion bill" for an additional runway, the company estimates building across the existing M25 path would incur a surplus of £2billion to £3billion more, with "all costs paid for by airlines".
Concerns were raised in its response to the Government’s consultation on Heathrow expansion, which is due to close at 11.45pm on Thursday (May 25).
The company believes a shorter runway that does not breach the M25, of 3,200 metres instead of 3,500 metres, would be perfectly operational.
It said in its submission that Heathrow is the best option for expansion and the consideration for a shorter runway could keep landing charges the same or lower than current levels.
Mr Walsh said: "Airlines were never consulted on the runway length and they can operate perfectly well from a slightly shorter runway that doesn't cross the M25.
"Bridging the M25 means years of disruption on a motorway already plagued by delays and congestion.
"As well as increased costs, this will have a huge impact not only on motorists but on local communities around Heathrow."
The government backed a third runway to be built at Heathrow in October last year.
Mr Walsh believes expanding across the motorway, which would include digging a tunnel or building a runway over the existing road, could be costly and cause delays.
"The airport has yet to produce a business plan that assesses the financial implications and risks of bridging the M25," he said.
"We will not pay for a runway that threatens both costs and delays spiralling out of control and where critical elements of the project could be undeliverable."
Heathrow said a shorter runway would have a greater impact on noise in the local community.
It is claimed this is due to larger aircraft, such as the A380, unable to use it for take-offs, limiting the respite period in parts of west London.
A Heathrow Airport spokesman said: "Like all major infrastructure projects, we have to balance several factors in order to deliver the increase in airport expansion that Britain needs: risk, constructability, passenger experience, quality, affordability and time.
"In each of these areas we have engaged expert advisers and consulted our airlines to ensure we get the right balance and the best outcome for our passengers, our local communities and the country as a whole."
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