Heathrow Airport has formally submitted its controversial proposals for a third runway, sparking renewed opposition from residents in Putney and across south west London who face hundreds of thousands more flights overhead.
The airport’s £49 billion expansion plan [pdf], delivered to the government on Friday, would see a new 3,500-metre runway built to the northwest of the existing airport, capable of handling up to 276,000 additional flights per year – bringing the total to 756,000 annual movements.
If approved, the scheme would increase passenger capacity from around 84 million to 150 million annually, making it one of the world’s busiest airports. The project includes a new terminal complex, closure of the aging Terminal 3, and a controversial plan to divert the M25 motorway through a tunnel beneath the new runway.
Putney Society leads local opposition
The Putney Society, which has campaigned against Heathrow expansion for decades, condemned the proposals as they were submitted.
“A third runway at Heathrow would mean hundreds of thousands more planes flying low over London each year, inflicting intolerable noise impacts on millions of Londoners throughout the day and much of the night,” the society said in a statement.
The group, which represents residents in an area already severely affected by aircraft noise, argued that “even without any expansion, Heathrow’s noise impacts are already very intrusive, and are massively worse than the impacts of all the other London airports combined.”
The society is calling for immediate improvements regardless of expansion plans, including “a complete ban on night flights for at least eight hours each night, so that people can have some hope of a decent night’s sleep.”
Challenging Heathrow’s economic arguments
The Putney Society also took aim at Heathrow’s central justification for expansion – its role as a business hub driving UK economic growth.
“Heathrow’s arguments about a hub airport supporting business travel and the UK economy are an outdated fiction,” it stated. “Today’s reality is that around 80% of Heathrow’s passengers are holidaymakers, and business travel through the airport is in long term decline, falling from 24 million in 2007 to 11 million in 2023.”
The campaigners argue that “the increasing demand for holiday travel can be met through the expansion plans of London’s other airports – with noise and other environmental impacts which are a tiny fraction of Heathrow’s, and probably also at much lower cost to UK taxpayers.”
Government backing despite local opposition
The proposals have strong government support, with Chancellor Rachel Reeves backing expansion as key to Labour’s growth strategy. The government says expanding Heathrow could drive growth, trade and tourism while creating over 100,000 jobs.
However, the scheme faces significant opposition beyond Putney. London Mayor Sadiq Khan said the expansion would have “a hugely detrimental impact on our environment,” while Liberal Democrat MP Munira Wilson described both the economic and environmental case as “in tatters”.
Putney MP Fleur Anderson has yet to comment on the new plans.
What the Plans Include
The £49 billion scheme breaks down into £21 billion for the third runway itself, £12 billion for a new terminal complex, and £15 billion for modernizing existing airport infrastructure. The costs have risen significantly since previous estimates, with the runway price increasing from £14 billion six years ago due to construction inflation.
The new runway would be 3,500 metres long and 60 metres wide, capable of accommodating all aircraft types. The airport claims this would enable at least 30 new daily airline routes by 2040, including approximately 10 new long-haul destinations.
Environmental groups have joined local residents in opposing the plans. Dr Douglas Parr from Greenpeace UK called it a “doomed scheme” that would release millions of tonnes of CO2 while benefiting only “a comparatively small group of frequent fliers”.
The Putney Society is also demanding better flight path management, calling for “an airspace re-design based on the performance of modern aircraft, so that they approach the airport more steeply, thereby flying over London and other towns at a greater height, so reducing the noise.”
Long Road to Delivery
Even with government support, the project faces a complex approval process. Heathrow hopes to obtain planning permission by 2029 and have the runway operational by 2035, but this requires significant changes to planning laws and regulatory frameworks.
The proposals represent the culmination of decades of debate about Heathrow expansion, with previous schemes approved in principle by governments in 2009 and 2018 before being shelved. For residents in Putney and across west London, the fight against what they see as an environmental and quality of life disaster continues.
As the government begins its review of the proposals over the summer, Heathrow is pressing for a green light by September to stay on track for the government’s ambitious timeline.
