Heathrow Airport has announced it is due to submit its proposal to build a new runway this summer, which will be fully funded by the airport
Due to the scale of the proposal, Heathrow expansion is classed as a Nationally Significant Infrastructure project (NSIP), meaning it will require a Development Consent Order (DCO). Heathrow’s push to expand comes at a time when debates continue to spark up on whether to approve future expansion of airports, such as Luton and Gatwick.
Heathrow Airport is currently at full capacity since the mid-2000s, whilst global demand for aviation is only growing. According to the International Air Transport Organisation, global air passenger demand reached record levels in 2024, and demand for aviation is expected to continue growing over the next decades. With Heathrow’s unrivalled status as the UK airport offering best connections to the world, and its role as the UK’s biggest port by value, enabling UK exports to the tune of more than £100 billion in 2024, it has a compelling case to increase its capacity.
An attempted expansion, marked by heavy resistance
However, the hurdles the airport needs to overcome for its expansion to be supported, and then approved, illustrate the difficulties that airports are currently facing, and the tough choices the Government must make when balancing two conflicting priorities: economic growth and net zero.
Prior to the Covid-19 pandemic, Heathrow was identified by the Airports Commission as needing a new runway due to capacity constraints. After a National Policy Statement (NPS) for a third runway at Heathrow was approved by the House of Commons under Theresea May’s premiership, the decision was overruled by the Court of Appeal in 2020, which considered the expansion as “unlawful” due to the country’s commitment to environmental protection. It was later challenged by the Supreme Court.
Heathrow’s rhetoric on economic growth
To shore up support, Heathrow is currently positioning itself to its investors, the UK Government, but also to the wider public as a long-term solution to unlock economic growth. Expansion could mean more economic growth in the Southeast of England, and for the whole United Kingdom, the airport argues. A study commissioned by the airport indicated that 60 % of that growth would boost regions other than the South-East. The study also highlights that the net benefits between 2024 and 2083 if expansion goes ahead would be over £24.7 billion. Overall, expanding Heathrow would boost the UK’s GDP, £17.1 billion per annum by 2050, equal to 0.43 % of the GDP. It would create jobs, increase economic growth, boost trade as well as improve infrastructure and connectivity.
How Heathrow could help the Government achieve growth
At present Heathrow expansion poses both a challenge and an opportunity to the UK Government. The Government is at somewhat of a crossroads in its pursuit of economic growth. In a speech given on economic growth, Chancellor Rachel Reeves pledged to boost the economy by supporting a third runway at Heathrow. This comes as the Chancellor faces a backlash to her controversial October budget. The budget raised taxes by £40bn, much of which will be paid by businesses. While the government argues it needs to raise the revenue, businesses are keen for the government to show that they understand business needs. Overall, Labour’s first budget has been met with controversy, and may indicate future challenges for public support of the Labour Party.
In this challenging context, one of the ways the government would be able to raise growth rates in the UK economy is to boost supply-side reform and by limiting hurdles to building new infrastructure, including transport, and boosting investor confidence in UK plc by signalling its ambitions.
The balance between environmental concerns and the economy
The challenge the Government is now facing is to demonstrate that the expansion would not threaten or undermine the UK’s net zero commitments, and it would instead signify a positive step forward for sustainable aviation.
Although economic growth is Labour’s top priority, approving Heathrow’s plans to expand has been highly criticised, and discord remains within the party. Some senior figures within Labour, such as Andy Burnham and Sadiq Khan, oppose Heathrow expansion because they perceive the environmental impact to be unacceptably high.
Reeves assured critics by committing to a full assessment of the project, including making sure it meets climate objectives. In a written statement to Parliament on 29 January, Transport Secretary Heidi Alexander pledged that a decision on granting development consent “must be delivered in line with the UK’s legal, climate, and environmental obligations.”
The Labour Government previously said it will cut carbon emissions by 80% by 2050. It has also backed a roadmap to the future of sustainable aviation fuels, which is part of the Jet Zero Strategy to deliver net zero aviation by 2050. At the beginning of January, the Sustainable Aviation Fuel Mandate came into force, which will pave the way for 22% of aircraft fuel supply to be sustainable by 2040. In addition, Alexander announced her department is investing £63 million in 2025 into the Advanced Fuels Fund to support the supply chain to develop and grow. However, environmental campaigners have criticised these plans, claiming that these technologies to are not developed at a full-scale yet and expressed scepticism.
Expanding Heathrow: driving growth and sustainability
Although developing technologies are still underway, approving a third runway at Heathrow Airport could mean a better and stronger future for sustainable aviation, through its potential to support supply chains in biofuels. Heathrow’s efforts at upscaling its use of sustainable aviation fuels are ambitious, highlighted in the airport’s sustainable strategy. The airport plans to use 11% of SAF by 2030, including charges to incentivise SAF use. The scale-up of SAF will be ensured by Heathrow’s SAF incentive scheme. Although the Government continues to drive investment on SAF to secure a sustainable future for aviation, upscaling would be met with challenges if not supported by the private sector.
Considering all these factors, both the Government and the airport have a significant challenge ahead, as developing, submitting and approving the Development Consent Order (DCO) will not be an easy task. Competing economic and environmental priorities is a pressing challenge for Heathrow, and it will have to continue to carefully consider its environmental impact and overcome scepticism and cynicism, especially as it engages with local communities and environmental groups.