On Tuesday 25 November 2025, the UK government formally chose Heathrow Airport’s own plan for a third runway as the blueprint for expansion at Britain’s busiest hub – a decision that puts the medieval village of Harmondsworth and its neighbour Longford on course for large‑scale demolition and revives bitter arguments about climate, regional inequality and the future of air travel. [1]
What the Government Has Approved – and Why It Matters Now
Ministers have picked Heathrow’s “north‑west runway” scheme: a 3.5km (2.2‑mile) third runway running across the M25 motorway, alongside a new terminal, satellite buildings and major changes to road and rail links around the airport. [2]
The overall investment package is estimated at £49bn, of which around £21bn is for the runway and related land and motorway works, £12bn for a new terminal, and £15bn for modernising the wider airport. [3]
If built as planned, the expansion would:
- Boost annual capacity from about 84 million to up to 150 million passengers
- Raise permitted flights to around 756,000 a year – roughly 760 more planes in the skies around London every day [4]
- Create what campaigners describe as the equivalent of “bolting an airport the size of Gatwick on to Heathrow” in climate terms [5]
Transport secretary Heidi Alexander has argued that Heathrow’s plan is the “most credible and deliverable option”, able to reach full planning consent by 2029 and open by around 2035, provided it passes four government tests on environmental impact, noise, economics and air quality. [6]
The decision follows Labour chancellor Rachel Reeves’ earlier pledge in January 2025 to push ahead with a third runway as part of a strategy to “make Britain the world’s best‑connected place to do business”. [7]
Harmondsworth: A Medieval Village in the Firing Line
For the people of Harmondsworth, the news is not an abstract infrastructure story – it is existential.
The village, recorded in the Domesday Book, is a pocket of rural England pressed up against the airport perimeter: two historic pubs, a classic village green, an 11th‑century parish church and the Grade I‑listed Great Barn, a vast medieval timber structure once dubbed the “Cathedral of Middlesex”. [8]
Campaign group Stop Heathrow Expansion warns that the early medieval village would be “decimated”, while neighbouring Longford would be “wiped off the map”, with up to 3,750 homes demolished or rendered unliveable by noise. [9]
Official and media assessments of the government‑backed option indicate:
- Large parts of Harmondsworth and virtually all of Longford are earmarked for demolition
- Local roads, rivers and green space in the Colne Valley Regional Park would be extensively diverted or built over
- Harmondsworth’s medieval church and Great Barn are expected to be preserved but would sit just outside the new airport boundary, beside a busy runway and realigned roads [10]
Residents have been living with the threat of a third runway for nearly two decades, through successive rounds of government approvals, U‑turns and court cases. Some locals describe already “stinking of jet fuel” and fear that even the parts of the village left technically standing could become uninhabitable once jets are taking off overhead every few minutes. [11]
Yet support is not unanimous. Earlier this year, some villagers told reporters they were prepared to see their “ancient village flattened” if it meant long‑promised investment and certainty at last, while others remain fiercely opposed, determined to fight the scheme all the way through the planning system and courts. [12]
Why Heathrow – and Not Birmingham or Other Regional Airports?
Today’s twist in the story comes via travel journalist Simon Calder, whose weekend Q&A tackles the question many Britons are now asking: why pour tens of billions into Heathrow, rather than expand Birmingham or other regional airports that have spare capacity? [13]
Calder notes that the government‑approved expansion could raise Heathrow’s passenger numbers by around 79%, to 150 million a year – “the equivalent of four Birminghams”, as he puts it. [14]
Yet the UK as a whole has plenty of underused runway capacity. Airports such as Cardiff, Prestwick and Doncaster Sheffield (currently mothballed) are often quiet, while Birmingham, Manchester and others would happily welcome more long‑haul flights. [15]
So why not simply redirect growth?
Calder’s answer rests on the “gravitational” nature of hub airports:
- Once airlines and connecting passengers cluster at a hub, its network of routes deepens
- That dense network, in turn, attracts yet more airlines and passengers
- Trying to shift traffic by political decree rarely works – airlines follow demand, not ministerial speeches [16]
He adds that, in theory, Birmingham could become more attractive to London‑area travellers once HS2 is complete and journey times fall to about 32 minutes from the capital. But even that, he argues, is unlikely to derail Heathrow’s expansion, because airlines rely on the critical mass of transfer passengers only a global hub can supply. [17]
In short, on 29 November the travel industry debate is not whether Heathrow is the obvious place for more flights – but whether the economic benefits really justify the enormous cost, disruption and environmental damage that come with ramping up an already dominant London hub.
Moving the M25: The Megaproject Beneath the Runway
One of the most eye‑catching elements of Heathrow’s winning bid is the re‑routing of the M25, the UK’s busiest motorway.
Under the chosen scheme:
- The new runway will physically cross the current route of the M25
- A section of the motorway will be shifted about 130m to the west and placed in a new tunnel beneath the airfield
- The motorway between junctions 14 and 15 will be widened and rebuilt, with new bridges, slip roads and junction layouts [18]
The motorway works alone are estimated to cost around £1.5bn and would entail years of construction next to one of the UK’s most heavily used stretches of road. [19]
Opponents, including the No 3rd Runway Coalition, argue that this is emblematic of what they call a “world’s most expensive airport expansion”. In a blistering statement after the government decision, the coalition’s chair accused ministers of “committing an act of national self‑harm” by backing a plan that would demolish several villages, displace up to 15,000 residents and still leave Heathrow struggling to raise the finance. [20]
Climate Targets, Noise and the Tests Heathrow Must Still Pass
Even with political backing, Heathrow’s third runway is far from a done deal.
The project must satisfy the UK’s legally binding climate commitments, as well as local air‑quality and noise limits. The government has promised to seek advice from the independent Climate Change Committee (CCC) to ensure the expansion is consistent with the pathway to net zero. [21]
The CCC has previously warned that aviation is already responsible for more greenhouse gas emissions than the UK’s entire electricity supply sector and that “net expansion” of UK aviation is incompatible with current carbon budgets unless offset by deep cuts at other airports. [22]
Environmental groups, from Friends of the Earth to local campaigners in west London, describe the government’s stance as a “reckless gamble with our future”, pointing to:
- An estimated additional 6 million tonnes of CO₂ annually from a third runway
- Thousands more residents newly exposed to aircraft noise
- Loss of habitats in the Colne Valley Regional Park and along rerouted rivers such as the Colne and Wraysbury [23]
There is also the likelihood of renewed legal challenges. Previous attempts to expand Heathrow were delayed when the Court of Appeal briefly ruled the project unlawful for failing to account for the Paris Agreement; that judgment was later overturned by the Supreme Court, but campaigners insist fresh evidence on climate science could reopen the argument. [24]
For now, ministers plan to update the Airports National Policy Statement (ANPS), with a full public consultation expected by summer 2026. Only once that is complete can Heathrow submit a detailed planning application, leading eventually to a public inquiry and a final government decision – currently targeted for 2029. [25]
Who Pays – and Will Passengers Feel the Cost?
While the expansion is meant to be privately financed, airlines and regulators are already ringing alarm bells about cost.
Major carriers including British Airways’ parent IAG and Virgin Atlantic have warned that a £49bn programme risks pushing up airport charges to levels that could make flying from Heathrow less competitive. The Civil Aviation Authority has launched consultations on how much Heathrow can recover from airlines through landing fees, and on which parts of the expansion count as “regulated assets”. [26]
Some airline bosses have compared the runway to a new “HS2 all over again” – a vast infrastructure bet that could end up over‑budget, delayed or partially built. [27]
From a traveller’s perspective, the stakes are mixed:
Potential upsides
- More long‑haul destinations from the UK’s main hub
- Greater competition on some routes, which could put downward pressure on base fares
- Improved resilience at an airport currently running at about 99% runway capacity, meaning fewer delays when things go wrong [28]
Potential downsides
- Higher ticket prices if airlines pass increased airport charges to passengers
- Continued concentration of flights in the South‑East rather than at regional airports
- Years of construction‑related disruption across west London roads and rail lines
As Calder points out, regional airports such as Birmingham, Manchester and Cardiff may yet benefit at the margins – particularly once HS2 improves their connectivity – but nothing in the government’s current approach suggests a fundamental rebalancing of UK aviation away from Heathrow. [29]
What Happens Next for Harmondsworth, Longford and Travellers?
As of Saturday 29 November 2025, the political decision has been made but the concrete is still years away.
For residents of Harmondsworth and Longford, the immediate future is more consultation documents, more legal arguments and more uncertainty over whether to stay put, sell up or campaign on. Activists pledge to fight on, while some homeowners quietly hope for generous compulsory purchase offers after decades of limbo. [30]
For travellers, nothing changes overnight – flights, terminals and prices in the short term will be driven more by airline competition and fuel costs than by a runway that may not open until the mid‑2030s.
But the big picture is clear: Heathrow’s third runway is back at the centre of Britain’s economic and environmental story. The coming months will show whether the government can convince courts, regulators, airlines – and the people of an ancient west London village – that tearing up this landscape is really the price of a better‑connected future. [31]
References
1. www.reuters.com, 2. www.theguardian.com, 3. en.wikipedia.org, 4. www.theguardian.com, 5. www.theguardian.com, 6. www.theguardian.com, 7. www.theguardian.com, 8. en.wikipedia.org, 9. stopheathrowexpansion.co.uk, 10. www.thesun.co.uk, 11. uk.news.yahoo.com, 12. www.thesun.co.uk, 13. www.independent.co.uk, 14. www.independent.co.uk, 15. www.independent.co.uk, 16. www.independent.co.uk, 17. www.independent.co.uk, 18. www.theguardian.com, 19. www.theguardian.com, 20. www.no3rdrunwaycoalition.co.uk, 21. www.theguardian.com, 22. news.sky.com, 23. www.theguardian.com, 24. en.wikipedia.org, 25. www.heathrow.com, 26. www.ft.com, 27. www.no3rdrunwaycoalition.co.uk, 28. en.wikipedia.org, 29. www.independent.co.uk, 30. stopheathrowexpansion.co.uk, 31. www.theguardian.com
