What we know about Heathrow third runway plans

Chancellor Rachel Reeves has given a strong hint that she will back plans to expand Heathrow Airport. Here's what we know about the proposals.

Hounslow, UK. 5th February, 2024. British Airways aircraft outside an aircraft hanger at London Heathrow. The Independent has reported that British Airways have
British Airways aircraft outside an aircraft hangar at London Heathrow. (Alamy)

Rachel Reeves has all but confirmed plans to back a third runway at Heathrow Airport as she prepares to make a speech on Wednesday.

The chancellor refused to be drawn on "speculation" over her announcement later this week, but dropped a strong hint when asked how the government would balance its climate commitments with economic growth.

“A lot (has) changed in terms of aviation,” she told the BBC’s Sunday With Laura Kuenssberg show. “There’s huge investment going on in electric planes, and also a third runway will mean that instead of circling London, flights can land at Heathrow.”

Asked if this meant an announcement on Heathrow expansion was imminent, Reeves said: “Well you’ll see the plans when we set them out... We are getting on and delivering, that will be good for investment and trade in our country and also good for families wanting to go on cheaper holidays as well.”

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While an expansion of Heathrow Airport is expected to boost the economy by tens of billions of pounds, critics claim the supposed benefits are overstated, while environmental campaigners and local people argue the noise pollution and carbon emissions would not be worth it.

Here, Yahoo News explains what we know about the plans so far.

Plans put forward by Heathrow Airport would see a third runway built to the north-west of the existing two.

If approved, it would mean building over parts of the Harmondsworth, Sipson and Harlington communities.

Proposals for a third runway at Heathrow would mean cutting through several villages. (PA
Proposals for a third runway at Heathrow would mean cutting through several villages. (PA)

Estimates on this have changed over the years.

It was expected to cost £14bn back in 2014, but according to the Times, the airport has informally told airlines the figure now sits between £42bn and £63bn.

Central to the Labour's pitch to voters last summer was the need to "rebuild Britain" and to boost economic growth.

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With this in mind, the government has put forward a number of measures to speed up planning and development of both housing and critical infrastructure.

In her interview with Kuenssberg, Reeves said the government has already signed off expansions at London City Airport and Stansted Airport, adding that the previous Tory leadership had "stalled" these decisions – providing a strong hint on where she stands on Heathrow.

“Let me be clear, already this government has signed off housing developments, a data centre infrastructure to support the AI and tech industry, we’ve supported onshore wind developments. We have supported a number of developments to get our country growing again," she told Sky News' Sunday Morning With Trevor Phillips programme.

LONDON, UNITED KINGDOM  JANUARY 21, 2025: Chancellor of the Exchequer Rachel Reeves leaves Downing Street after attending weekly Cabinet meeting in London, United Kingdom on January 21, 2025. (Photo credit should read Wiktor Szymanowicz/Future Publishing via Getty Images)
Chancellor Rachel Reeves has criticised the previous Tory government for 'stalling' airport expansion plans. (Getty Images)

So, what economic benefits would a third runway bring? Well, a 2015 report by the independent Airports Commission suggested it would boost UK economic growth by £150bn over 60 years and create 60,000 new jobs.

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A more conservative government assessment the following year suggested an economic boost of £61bn over 60 years, with the potential for 77,000 additional local jobs by 2030, while giving passengers "greater choice" and putting "downward pressure on air fares".

These are all figures from around a decade ago, and successive governments have not put out a detailed economic assessment since then.

In 2020, an assessment by the New Economics Foundation suggested a third runway at Heathrow could drain £43bn from the economies of the UK's wider regions as 27,000 jobs move to London and the South East as a result of the expansion.

The think-tank has separately suggested that by 2040, three quarters of passengers using an expanded Heathrow would be transferring to flights outside the UK, casting doubt on wider regional benefits.

The No 3rd Runway Coalition has said estimates on economic returns have "have historically been overstated", adding that "increases to the costs of construction, inflation and changes to the cost of carbon abatement have further weakened the case for expansion".

Analysis by the New Economics Foundation published earlier this month suggests that five years of Heathrow expansion would mean the release of an additional 51 million tonnes of CO2 equivalent.

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It says this would "wipe out" the benefits of the government's clean power plan, and that a third runway, combined with an expansion of Luton and Gatwick, "would create very significant climate damage", even after considering efficiency savings and alternative fuels.

"Even under the previous government’s Jet Zero Strategy, which is widely considered to be extremely optimistic about the scope for emissions reduction in aviation, there is expected to be very significant climate damage from air travel remaining in 2050," the foundation says.

Despite Reeves' enthusiasm for investment into electric planes, some experts suggest we shouldn't expect to see these vehicles entering the mainstream until around 25 years' time.

The No 3rd Runway Coalition also warns of a significant "negative effect" on air pollution – with no enforcement plans in place should Heathrow breach legal limits, as well as an additional two million people being exposed to increases in noise pollution.

Not everyone in the Labour party is on board with an expansion, with The Guardian reporting that energy secretary Ed Miliband warned cabinet colleagues that it would likely put the UK in breach of its legally binding carbon budget.

This limit on greenhouse gases helps keep the government on track to meet its target of net zero emissions by 2050.

London mayor Sadiq Khan, a vocal critic of Heathrow expansion, said his views on a new runway "haven't changed", adding that while the aviation sector is important for jobs, "we face a climate crisis and a climate emergency".

London, UK. 20th Jan, 2025. Sadiq Khan, Mayor of London. The annual City Hall Holocaust Memorial Day service is a joint event with the Mayor of London, London Assembly, Holocaust Educational Trust and the Holocaust Memorial Day Trust. The ceremony commemorates victims of the Holocaust and provides a time of reflection for those affected by more recent genocides. Testimonials are also heard from Holocaust survivor Eva Clarke BEM, and Smajo Beso OBE, a survivor of the Bosnian genocide. Credit: Imageplotter/Alamy Live News
Sadiq Khan has said his views on a third runway 'haven't changed'. (Alamy)

Homeowners in Harmondsworth, many of whom have lived in limbo over the prospect of being forced to sell their homes to make way for expansion, spoke to Yahoo News about their plight.

“It’s terrible to think of how half of this village would just disappear," said vicar Richard Young, 59. “You would end up with just a bunch of buildings and no viable community… It's really had a devastating effect."

Local have raised concerns about the potential expansion.
Local have raised concerns about the potential expansion.

Julian Mosses, 74, whose home would be demolished if he were issued a compulsory purchase order, said: “This is an ideal community village. I’ve lived here happily for more than 40 years and I don’t want to move… It just doesn’t make sense.

“And what am I meant to do if I’m forced out of my home? I won’t be able to afford an equivalent – because of the low prices offered for these homes.”