Two decades and 0.2C of global warming after a Labour government last weighed in on Heathrow, the answer appears the same: keep digging. Rachel Reeves’s anticipated backing for a third runway would again prioritise growth and the global economy over climate. Interviewers are even asking Ed Miliband if he would resign in protest – a question that last troubled the headlines in 2009.
Airport expansion in the UK, especially in the south-east of England, is coming regardless, with four other London-branded airports sneaking ahead in the queue. Stansted and City have both been granted permission to grow. Fully developed plans that will radically alter the scale of Gatwick and Luton have, meanwhile, been through the inspectorate and await ministerial signoff.
And now the spectre of a Heathrow scheme that would overshadow all of them in terms of additional flights, pollution and carbon emissions has been revived. Is the nation ready to wake up and smell the kerosene?
Perhaps the most salient lesson since Gordon Brown’s government rubber-stamped Heathrow’s plans 15 years ago is that no third runway has yet been built. Some of the factors that halted it were temporary: the coalition politics that blocked the runway, before creating a commission that chose it again in 2015; then the pandemic and collapse of international travel.
But others persist: environmental and noise objections, the logistics of expanding the airport across Britain’s busiest motorway, and the need to knock down swathes of neighbouring villages, blighted though they are.
Heathrow’s chief executive, Thomas Woldbye, spent 2024 working on a blueprint to grow the airport’s capacity by making the most of its existing infrastructure. Bigger investment decisions were on hold during the protracted sale of the stake of the biggest shareholder, Ferrovial, to the Saudi investment fund and private equity investor Ardian, which completed in December.
Heathrow’s new owners will want a clear government endorsement before relaunching a scheme whose costs were estimated at £19bn back in 2015. The airport will also want clarity on critical associated policy: on its own regulation, airspace modernisation changes and planning reform.
The first – how the Civil Aviation Authority (CAA) allows Heathrow to charge its airlines – will shape how it funds and profits from expansion, and whether those airlines endorse or object to runway plans. The second, another ongoing piece of work by the CAA, could affect the number of flights and which communities get overflown – potentially with hefty compensation for noise.
A third is planning reform, particularly if, as the Starmer government suggests, permission could be speeded up and legal challenges curbed. After the runway was approved by parliament, a year of court battles ensued. Long mandatory public consultation and mammoth planning inspections lie ahead for the airport before ministers can sign off the development consent order (DCO). The DCOs for Gatwick and Luton, however, are already on transport secretary Heidi Alexander’s desk – and may yet prove the most important factor.
Luton’s decision, due at the start of 2025 but pushed back to with a deadline of 3 April, potentially allows passenger numbers to rise by 40% to 32 million per year. The economic growth is also direct: public ownership means profits from expansion will fund the local council, rather than foreign shareholders.
The decision on Gatwick, due by 27 February, gives a similar proportionate rise to an already much bigger airport. Extending an existing emergency runway and moving it 12 metres north will allow it two strips – with over 100,000 more planes taking off and landing, growing to serve 75 million passengers a year. Chief executive Stewart Wingate says the airport can “be a major part of the government’s drive for growth … through a £2.2bn, privately financed, shovel-ready investment”.
Although Gatwick plays down the idea of “either/or” competition for a new runway, which defined the Airports Commission’s process when choosing Heathrow, it is clear that many in London – including Alexander’s old boss, Mayor Sadiq Khan – back Gatwick as a less troublesome alternative. Khan told the London Assembly last week that a go-ahead for Gatwick would be a “slam dunk” against any possibility of Heathrow getting another runway.
While environmentalists’ key concern, total carbon emissions, will not be improved by where the planes take off and land, noise pollution is a pivotal factor for many opponents.
One possible benefit of airspace modernisation is to ameliorate the worst effects of noise, with steeper take-offs and distributed flight paths. But it also complicates the picture for Heathrow: the delayed design for (and public consultation on) where planes fly is now anticipated in 2027. According to Paul Beckford of campaign group Hacan: “People who have bought houses in London and the south-east could find themselves under a new flight path – and those who are currently overflown could experience greater intensity and noise.”
Local campaigners at Gatwick Area Conservation Campaign (GACC) are sceptical of Gatwick’s own pledges on the “noise envelope” – which even the airport admits will grow, despite hopes for quieter planes. But the numbers of people deemed by the CAA to be significantly affected by Gatwick noise in Sussex is just 1.4% of the population disturbed by Heathrow (4,300 v 309,200 people).
Collectively, the permitted growth of the other four “London” airports will see hundreds of thousands more flights a year – more than an expanded Heathrow. But it may not yet prove enough for the chancellor: Heathrow has long argued its own “hub capacity”, with transfers and connections to the UK’s nations and regions, is uniquely valuable for business and trade. A spokesperson said: “Growing the economy means adding capacity at the UK’s hub airport, which is full.”
