Transport Secretary Heidi Alexander has approved plans for a second runway at London Gatwick Airport, as the government looks for economic growth opportunities.

The £2.2bn privately-financed project involves in effect moving the current Northern Runway 12 metres to bring it into regular use, as well as other developments, including extending the size of terminals.

The airport says its plans will bring jobs and boost the local economy. But there has long been opposition from campaigners and groups worried about the impact on the surrounding area.

Gatwick currently handles about 280,000 flights a year. It says the plan would enable that number to rise to around 389,000 by the late 2030s.

A government source has described the plans as a “no-brainer for growth,” adding that “it is possible that planes could be taking off from a new full runway at Gatwick before the next general election.”

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

The plans approved by Ms Alexander would include adding 40,000 more flights before the second runway opens, and 70,000 more – almost 190 a day – once it is fully up and running.

The airport says that passenger numbers could rise to up to 80 million.

Currently, the Northern Runway is currently only used for taxiing or as a back up.

The second runway would be used for short haul flights, with capacity also freed up for more long-haul services from the main runway.

The decision to approve the expansion plan had been expected in February, but at the time, the transport secretary only said she was “minded to grant consent” for the Northern Runway planning application.

It emerged planning inspectors had expressed concerns over the effect the proposals would have on several aspects on the area surrounding the airport, including traffic and noise.

In April, Gatwick Airport agreed to stricter noise controls, an enhanced insulation scheme for nearby residents, and having 54% of air passengers using public transport before the Northern Runway opened.

To achieve this target, the airport said, third parties – including the Department for Transport – would need to “support delivery of the necessary conditions and improvements required to meet this target,” giving the example of reinstating the full Gatwick Express rail service.

Before the Covid-19 pandemic, the Gatwick Express ran a service of four trains per hour non-stop between the airport and London Victoria, this was reduced to two trains per hour from 2022.

Gatwick Airport also proposed a cars-on-the-road limit if the 54% target could not be met before the first use of the Northern Runway to address possible road congestion concerns.

It added that if neither the target nor the cars-on-the road limit could be met, the runway plans would be delayed until the required £350m of road improvements had been completed.

“This would make sure any additional road traffic flows can be accommodated and any congestion avoided,” the airport said.

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

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

Chris Curtis, who chairs the Labour Party’s growth group, welcomed the approval but said “radical planning reform” was needed to enable future projects to be completed more swiftly.

Shadow transport secretary Richard Holden welcomed the decision as “a vital step towards driving economic growth”.

But he said approval should have been made months ago and accused Labour of creating “uncertainty for businesses and local communities”.

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

Green Party leader Zack Polanski said approval of the expansion plan was a “disaster for the climate crisis”.

Hannah Lawrence, spokesperson for Stay Grounded, said “We need an immediate end to airport expansion and money put into improving sustainable transport such as trains.”

In February, 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.

Unite the Union general secretary Sharon Graham 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”.

Sally Pavey, chair of Communities Against Gatwick Noise Emissions (CAGNE), said she was 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’s is the latest in a string of airport expansion approvals, most recently Luton’s in June.

The government has also expressed support for a third runway at the country’s biggest airport, Heathrow, but that would be a much more complex, costly and controversial project.

Air travellers are facing another day of disruption at several European airports including Heathrow, after a cyber-attack knocked out a check-in and baggage system.

There were hundreds of delays on Saturday after the software used by several airlines failed, with affected airports boarding passengers using pen and paper.

Brussels Airport said it had “no indication yet” when the system would be functional again and had asked airlines to cancel half their departing flights for Monday.

RTX, which owns software provider Collins Aerospace, said it was “aware of a cyber-related disruption” to its system in “select airports” and that it hoped to resolve the issue as quickly as possible.

It identified its Muse software – which allows different airlines to use the same check-in desks and boarding gates at an airport, rather than requiring their own – as the system that had been affected.

The company has yet to disclose what went wrong or how long it expects the outage to last, but said on Sunday it will “provide details as soon as they are available”.

Brussels Airport said only manual check-in and boarding are possible “due to a cyberattack against Collins Aerospace”.

It added disruption would continue into Monday “because Collins Aerospace is not yet able to deliver a new secure version of the check-in system”.

Heathrow said on Sunday that efforts to resolve the issue were ongoing. It declined to say whether or not the issue was a cyber attack.

It apologised to those who had faced delays but stressed “the vast majority of flights have continued to operate”, urging passengers to check their flight status before travelling to the airport and arrive in good time.

The BBC understands around half airlines flying from Heathrow were back online in some form by Sunday – including British Airways which has been using a back-up system since Saturday.

There have already been more cancellations across Heathrow, Berlin and Brussels so far on Sunday than throughout Saturday, according to flight data firm Cirium, though not all of these are due to the cyber-attack.

There were hours-long queues on Saturday and some 47% of Heathrow’s departing flights were delayed, according to flight tracker FlightAware. Additional staff were at hand in check-in areas to help minimise disruption.

By Sunday afternoon, FlightAware data showed the number of delayed flights from Heathrow had fallen from levels seen on Saturday.

Virgin Atlantic, which operates from Heathrow, said it was “aware of a technical issue impacting check-in systems at a number of airports including London Heathrow which may result in some delays to departures”.

It added that “currently all Virgin Atlantic flights are scheduled to depart as planned”.

Naomi Rowan, from Sudbury in Suffolk, was supposed to be moving to Costa Rica with her dog Dusty, but both are now in a hotel after their Air France flight from Heathrow on Saturday was affected by the cyber attack.

She said staff were boarding passengers with pen and paper due to the outage but told her they were unable to board Dusty without the electronic system.

“I had a cry, booked a hotel and managed to get through to Air France on WhatsApp, who say the next available flight for me is Monday,” she said.

Europe’s combined aviation safety organisation, Eurocontrol, said airline operators had been asked to cancel half their flight schedules to and from the airport until 02:00 on Monday due to the disruption.

Meanwhile, Dublin Airport said that while the technical issues persisted and some airlines were continuing to check in manually, it was expecting to operate a full schedule on Sunday.

A spokesperson told the BBC: “Passengers are advised to contact their airline directly for updates on their flight.”

Dublin Airport previously said that Cork Airport, which is owned by the same parent company, had experienced a “minor impact” from the cyber-attack – but Cork Airport has since said it has faced no disruption with all services operating as normal.

Berlin Brandenburg Airport is asking travellers to use online or self-service check-in instead of the desks while the outage is ongoing.

It said there had been 12 cancellations in and out of the airport on Saturday, but that delays were generally less than 45 minutes.

A National Cyber Security Centre spokesperson said on Saturday that it was working with Collins Aerospace, affected UK airports, the Department for Transport and law enforcement to fully understand the impact of the incident.

The European Commission, which plays a role in managing airspace across Europe, said it was “closely monitoring the cyber-attack”, but that there was no indication it had been “widespread or severe”.

Transport Secretary Heidi Alexander also said she was aware of the incident and was “getting regular updates and monitoring the situation”.

It was only last July that a global IT crash due to a faulty software update from cybersecurity firm Crowdstrike caused disruption to aviation, grounding flights across the US.

Analysts said at the time that the incident highlighted how the industry could be vulnerable to issues with digital systems.

Additional reporting by Rozina Sini