A second runway at Gatwick Airport has been backed by government, providing measures to reduce noise are put in place.

Transport Secretary Heidi Alexander said she was “minded to approve” the expansion. Some MPs, local authorities and residents are strongly opposed.

The airport wants to move its northern runway, which is currently only used for taxiing or as a back up, and make it operational by the end of the decade.

The transport secretary’s support does not guarantee the expansion will go ahead as it would still need planning permission.

If permission is granted, work would start almost immediately, the BBC understands. The £2.2bn expansion will be funded through private investment.

“I am issuing a minded to approve decision that provides some additional time to seek views from all parties on the provisions, prior to a final decision,” Alexander said in a written ministerial statement on Tuesday.

Gatwick has until 24 April to respond to demands for it to include measures, such as noise mitigation and having a proportion of passengers travelling to the airport via public transport, in its overall plans before a final decision will be made in October.

Stewart Wingate, Gatwick Airport chief executive, said following the latest announcement that the government has “outlined a clear pathway to full approval later in the year” and that the airport would “engage fully” in the process.

The Transport Secretary’s support for expansion comes as the government is looking at ways to boost economic growth in a bid to boost living standards, with Chancellor Rachel Reeves backing a third runway at Heathrow last month.

Gatwick, in West Sussex, is Europe’s busiest single runway airport, with more than 40 million passengers using it last year.

On Tuesday, Alexander told industry leaders aviation was good for economic growth and said she was “not some sort of flight-shaming eco warrior“.

The growth arguments for expanding Heathrow and Gatwick, the UK’s two largest airports, differ with the former catering for more freight traffic relating to international goods trade.

An extra runway at Gatwick would see capacity increased for holidaymakers and business travellers, particularly for short-haul destinations, as opposed to Heathrow’s longer-haul flights.

Gatwick managers have said that with 55 take-offs and landings in a busy hour, the airport is “full”.

Being able to use both runways could increase the number of departures by 50,000 a year by the end of the 2030s, the airport argued.

It said some 30,000 of those flights are planned to depart from the north runway which will only be used for departures and not landings.

But there is strong opposition to any expansion, particularly from climate campaigners.

Greenpeace UK policy director Douglas Parr said the extension would not drive economic growth. “The only thing it’s set to boost is air pollution, noise, and climate emissions,” he added.

Alex Chapman, senior economist at left-of-centre think tank New Economics Foundation, also argued the move would not create new jobs, but would just shift them from other parts of the country.

“People are already perfectly able to catch cheap flights on holiday or travel for business,” he added.

Union Unite backed Gatwick having a second runway, but warned it would need “to come with guarantees of well paid, unionised jobs and proper facilities for workers”.

Bronwen Jones, development director at Gatwick, said a second runway would be “a win for everyone”.

She said it would create more flight slots across both runways.

“That allows us to offer new routes, new airlines, more frequencies on existing routes, so that passengers have more choice.”

Sally Pavey, chair of Communities Against Gatwick Noise Emissions (CAGNE), is worried about “uncontrollable noise, ramifications on the roads, decline in air quality… and climate change”.

“We can’t keep ignoring climate change and it would be wrong to allow a new ‘bucket and spade’ runway, as we put it, at the expense of residents and the economy,” she said.

The group would take legal action through a judicial review if the expansion goes ahead, she added.

Gatwick said it has committed to reducing noise levels to below those of 2019 – which CAGNE says was one of the worst years for noise.

On Wednesday the government’s independent advisers, the UK climate change committee (UKCCC), recommended that to meet the country’s climate goals the amount of planet-warming gases released by the country’s aviation sector needed to fall by 17% compared to 2003 levels.

Some of the pollution from flying, it said, could be reduced by switching planes to sustainable aviation fuel (SAF) and by capturing the planet-warming gases released.

But experts think it could be challenging to obtain the feedstock, like corn grain or food waste, needed to make SAF.

The UKCCC said the best way to reduce the industry’s impact on climate change would be to significantly slow the demand for flying.

At current levels demand is expected to grow by 53% by 2040, while the UKCCC says this should be closer to 16%.