Heathrow Airport has revealed details of its plan to expand and modernise the airport at a cost of £49bn.

Thomas Woldbye, CEO of Heathrow Airport, said expansion was “urgent” as the airport was currently working at capacity, “to the detriment of trade and connectivity”. The work would be funded by private finance.

The government has backed plans for a third runway, with Chancellor Rachel Reeves saying it would “make Britain the world’s best connected place to do business”.

However, the plans face opposition from environmental groups, politicians, and locals. London’s mayor Sir Sadiq Khan said it would have a “severe impact on noise, air pollution and meeting our climate change targets”.

The plans come a day after the deadline set by the government for parties to submit proposals.

Heathrow’s plans, which it estimates would be completed within a decade, include:

• Creation of a third runway, called the “North-Western Runway”, which would be up to 3,500m (11,500 ft) long. Heathrow bosses say this will increase capacity to 756,000 flights and 150m passengers a year – it currently serves about 84m
• A new terminal called T5X, expanding Terminal 2 and three new satellite terminals. It would close Terminal 3
• Enhancement of local rail connections, plus walking and cycling routes
• Diversion of the M25, which would involve a new road tunnel under the airport, and widening the motorway between junctions 14-15
• Creation of two new Heathrow parkways
• Improvements to Heathrow’s bus and coach stations.

Heathrow said it would cost £21bn to build the third runway, which includes procuring the land, changing the M25 and other associated infrastructure costs while building the new terminal would be £12bn and modernising the current airport’s infrastructure £15bn. Due to rounding, it will total £49bn.

A spokesperson added the plans would grow the UK economy by 0.43% GDP.

The plans revealed by Heathrow were welcomed by business groups and airline companies.

A joint statement from the Confederation of British Industry, British Chambers of Commerce, MakeUK, Federation of Small Businesses and Institute of Directors, said it was “an investment in the nation’s future”.

It added: “The benefits are clear: for exporters, it opens up vital access to major and emerging markets; for visitors, it enhances global and domestic connectivity; and for businesses, it unlocks billions in private investment, strengthening supply chains, creating jobs, and driving skills across the country.”

John Dickie, chief executive of BusinessLDN, said as the airport was currently operating at full capacity, the expansion would give businesses “better connectivity to overseas markets and support Britain’s growth”.

He added it would also help achieve the government’s target of 50 million international visitors per year to the UK.

Mr Woldbye said Heathrow’s submission was in line with the aviation industry’s target to be net zero by 2050.

He added that Heathrow was “the airport in the world with the highest uptake of Sustainable Aviation Fuel”, and that planning permission would not be granted by government unless legal limits of emissions were adhered to.

However, the plans were heavily criticised by groups who called the environmental justifications for the plans as “hopeful marketing spin”.

Dr Douglas Parr, policy director for Greenpeace UK, said the government had “decided yet again to prioritise more leisure opportunities for a comparatively small group of frequent fliers, whilst the rest of us have to live with the consequences of their disproportionate polluting”.

He suggested a “frequent flier levy”, and said no expansion should take place until there was a solution to the “pollution problem”.

His concerns were echoed by politicians including Sir Sadiq who said he remained “unconvinced” that hundreds of thousands of additional flights each year would not have a “hugely detrimental” impact.

He added City Hall would “carefully scrutinise” the impact the extension would have on people living in the area and the “huge knock-on effects for our transport infrastructure, which would require a comprehensive and costed plan to manage”.

Chancellor Rachel Reeves said the applications that have come in “will include investment in the infrastructure, for example, the changes around the M25 to make airport expansion necessary”.

She added: “Airport expansion is essential if we’re going to seize the opportunities, and this government are absolutely determined to seize the opportunities that come from being an open trading economy.”

Asked about the mayor of London’s objections, Reeves said: “These are decisions the national government make, and this Labour government backs Heathrow expansion, backs the third runway at Heathrow.”

Munira Wilson, the Liberal Democrat MP for Twickenham, said Heathrow is already the single largest polluter in the UK.

She added: “The Climate Change Committee itself has said expansion would put the UK’s climate goals at risk.

“It’s also clear we can’t rely on the silver bullet of Sustainable Aviation Fuels to save the day.”

Green Party deputy leader, Zack Polankski, said the plans were being delivered “regardless” of the environmental impact.

“If Labour’s environmental commitments were worth the paper they’re written on, these proposals would never have seen the light of day,” he said.

Local residents living in Harmondsworth, near the airport, told the BBC earlier this year a third of the village would be destroyed if a third runway was to go ahead.

Heathrow’s plans follow the publication of a rival proposal by the Arora Group, which has outlined a way to expand the airport without needing to redirect the M25.

Owner of the group, hotel tycoon Surinder Arora, said the creation of a third runway and a new terminal, under his plans, had a cost estimate of under £25bn, not including the redevelopment of the airport’s existing central area.

The proposal crucially does not involve an expensive alteration to the M25, as the group said it was possible to build a 2,800-metre (9,200 ft) third runway instead of the full-length 3,500-metre (11,500 ft) runway planned by the airport.

Arora Group said its plan, called Heathrow West, could have a new runway fully operational by 2035, while a new terminal would open in two phases, in 2036 and 2040.

When asked about the added expense of altering the M25 to accommodate a new, third runway, Heathrow’s CEO said: “The whole conversation about the M25 has been slightly exaggerated”, and that disruption to drivers would be minimal.

“We will build a new and much better M25, 100m (330 ft) to the west of the current one. It will be wider and it will be safer and it will have more capacity,” Mr Woldbye added.

He said plans to create a much shorter runway to avoid moving the M25 – like the one proposed by The Aurora Group – would “not provide the capacity that we and the airlines need”, but said the airport would be open to a discussion with airlines about building a shorter runway if it could deliver the same benefits.

Transport Secretary Heidi Alexander said the two proposals were a “significant step towards unlocking growth, creating jobs, and delivering vital national infrastructure”.

“We’ll consider the proposals carefully over the summer so that we can begin a review of the Airports National Policy Statement later this year,” she added.

The London Borough of Hillingdon, which contains the whole of Heathrow, reiterated its opposition to expansion, calling the airport’s plan “a glossy pitch”.

It said Heathrow’s claims of full private funding “don’t stand up to scrutiny – the public would ultimately bear the cost of tunnelling the M25, surface access works, and noise mitigation”.

BBC London’s political editor Karl Mercer said: “History has not been kind to plans to build a third runway, whoever has put them forward, and whichever colour government is in power.

“Gordon Brown’s Labour government supported Heathrow expansion in 2009 – that didn’t happen.

“Then during Conservative Theresa May’s reign in 2018, MPs voted overwhelmingly in support of a third runway – only for a series of court challenges and then Covid to put an end to those plans.

“There are plenty of Labour MPs in the capital who are still strongly opposed to expansion – 28 voted against it last time and most are still in the House.

“Having bidders interested is only half the battle – the hardest half will be getting it delivered.”

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