Gatwick Airport’s £2.2 billion second runway plan has been given the go-ahead by Transport Secretary Heidi Alexander.

In the privately-financed project, the West Sussex airport will move its emergency runway 12 metres north, enabling it to be used for departures of narrow-bodied planes such as Airbus A320s and Boeing 737s.

This will enable it to be used for about 100,000 more flights a year.

Ms Alexander backed the scheme as a “no-brainer” for economic growth, a Government source said, suggesting flights could take off from the new full runway before 2029.

The Cabinet minister is satisfied with adjustments made, covering issues such as noise mitigation and the proportion of passengers who would travel to and from the airport by public transport.

It comes after the Planning Inspectorate initially rejected the airport’s application and earlier this year recommended Ms Alexander should approve the project if the changes were made.

New commitments include Gatwick’s management setting its own targets for the proportion of passengers who travel to the airport by public transport, rather than a legally binding target.

Residents affected by more noise will be able to ask Gatwick to cover the costs for triple-glazed windows.

Homeowners living directly beneath the new flight routes who choose to sell could have their stamp duty and reasonable moving costs paid, as well as estate agent fees of up to 1% of the purchase price.

Gatwick says its plans will create £1 billion per year in economic benefits, and generate an additional 14,000 jobs.

A Government source told the PA news agency: “The Transport Secretary has cleared Gatwick expansion for take-off.

“With capacity constraints holding back business, trade and tourism, this is a no-brainer for growth.

“This Government has taken unprecedented steps to get this done, navigating a needlessly complex planning system, which our reforms will simplify in future.

“It is possible that planes could be taking off from a new full runway at Gatwick before the next general election.

“Any airport expansion must be delivered in line with our legally binding climate change commitments and meet strict environmental requirements.”

Local campaigners opposed to expansion are concerned about the impact on surface transport, noise, housing provision and wastewater treatment, but the airport insists it has conducted “full and thorough assessments” of those issues.

CAGNE, an umbrella aviation community and environment group for Sussex, Surrey and Kent, said it stands ready to serve a judicial review funded by residents and environmental bodies.

The group said: “We know this Government cares little for the environmental impact aviation is having on our planet and Gatwick’s neighbours, but not to demand that Gatwick pays for the infrastructure, the onsite wastewater treatment plant, and noise impact is unlawful in our book.”

The Labour Government’s backing of a third runway at Heathrow Airport in its bid to grow the economy has also drawn criticism from environmental groups and opposition politicians.

Green Party leader Zack Polanski described ministers’ support of a second Gatwick runway as a “disaster”.

He said in a statement: “It ignores basic climate science and risks undermining efforts to tackle the climate crisis.

“Labour keeps wheeling out the same nonsense about growth, but at what cost? What this really means is more pollution, more noise for local communities, and no real economic benefit.”