More than 10,000 homes may have to be demolished around Heathrow because of a massive increase in air pollution if a proposed new runway is built, it is reported.

This far exceeds original estimates outlined by the government last week during its announcement of possible expansion plans at Heathrow and other UK airports.

It said then that only 260 homes would have to be demolished to make way for a new 2,000-metre runway in west London.

However, notes on air quality, which form part of the consultation documents issued at the time of the announcement, say people exposed to pollution above EU limits may also have their homes pulled down.

Locals in west London oppose any expansion

The Times reports that the document for the south-east states: "By 2015 some 35,000 people could be exposed to an exceedence of the annual average EU limit for nitrogen dioxide if a third runway was built."

This could be reduced to 5,000 people, but only if the aviation industry makes much faster improvements in engine technology.

Oxides of nitrogen cause lung diseases and breathing problems.

The areas near Heathrow facing the greatest threat from pollution are Sipson, Harlington, Hayes and West Drayton.

The airlines would have to provide reassurances they were dealing with the pollution issue if they are to make the case for the new runway.

This could include responsibility for the cost of funding the purchase and demolition - where necessary - of properties, although they are likely to argue that compensation should come from the government.

'Minimising the impact'

A spokesman for the Department of Transport said: "In answer to the question whether the government would be prepared to see the purchase and demolition of the houses of 35,000 people, or how many houses we would accept being demolished, we have made clear that we want to minimise the adverse impacts of growth in aviation.

"Minimising the impact on people's homes is an important part of this objective."