Gatwick is extending its noise insulation scheme to stretch 30km and has challenged Heathrow to follow suit, as the battle for an extra runway hots up.

As Heathrow launched its consultation about plans for a third runway at the airport today, Gatwick announced it would offer noise insulation to an extra 860 homes within the 60 Leq noise contour.

The airport, which itself wants a second runway, challenged Heathrow to match its offer - meaning it would have to cover an estimated 70,000 households, from Windsor in the west to Putney in the east.

Gatwick's map showing which new areas would be covered were Heathrow to copy its more generous noise insulation scheme
Gatwick's map showing which new areas would be covered were Heathrow to copy its more generous noise insulation scheme

Heathrow already offers free sound proofing measures, including double glazing, ventilation and loft insulation, to some 40,000 homes under the flight path.

Gatwick's current scheme covers just under 1,200 homes within the noisier 66 leq contour. It claims the new offer, covering a total of 30km of rural land from east to west, will be the most generous in the world when it is rolled out in April 1 this year.

Gatwick's announcement marks a fresh intensity in the fight for a new runway, with the Airports Commission having whittled down the options to a shortlist of three: two at Heathrow and one at Gatwick.

Gatwick's chief executive Stewart Wingate said: "The leadership position we have taken on aircraft noise today shows the importance we attach to our local community as we continue to compete and grow from a single runway, but also as we plan to build a second.

"We understand that the public's tolerance to noise is much lower than it was which is why we are now extending our noise insulation scheme to cover the 30km flight path east and west of the airport."

The Leq scale is used to measure average noise over an extended period; 66 Leq is comparable to that from a vacuum cleaner, while 60 Leq is that of a nearby conversation.

A Heathrow spokeswoman said: "Around 40,000 homes are eligible for noise insulation under Heathrow's current noise schemes.

"Our proposal for a third runway would see fewer people affected by noise than today due to quieter aircraft and new flight paths. We have said that if government supports a third runway at Heathrow then any areas which do experience new noise or a significant increase in noise should be eligible for free noise insulation."

Deputy Hounslow Council leader Colin Ellar said: "I think any resident affected by aircraft noise will welcome a robust soundproofing package that helps to lessen the impact on their lives.

"Gatwick has certainly laid down the gauntlet to Heathrow to improve the mitigation it provides for thousands of residents and schools underneath the flight path.

“We don't want Heathrow to close. That would be catastrophic for the local economy. We do want a better not a bigger airport, and that includes the airport being a better neighbour to our residents, schools and businesses."

Heathrow today launched a six-week consultation about its plans for a new runway to the north-west of the existing two.

Booklets are being sent to 140,000 homes and business around the airport asking for people's views on the new runway's operation. These will be used to revise its final proposal, due to be submitted to the Airports Commission in May.

People will also be able to have their say at a series of exhibitions, with locations including Brentford Holiday Inn on March 6, from midday to 8pm, and Hounslow Civic Centre on March 8, from 9.30am to 4.30pm.

John Stewart, chairman of anti-Heathrow expansion campaign group HACAN, has branded the consultation a 'PR exercise', claiming the real issue is whether a new runway is needed in the first place.