Government launches Heathrow third runway consultation as £49bn expansion advances

The Government has published a draft national policy statement on Heathrow expansion and launched a public consultation running for more than 10 weeks, marking a significant step forward for one of Britain's most contested infrastructure projects. The move brings the prospect of a third runway at the airport closer than at any point in years.

The consultation, which runs until 1 September, invites businesses, communities and the public to comment on how a third-runway scheme would address four key tests: air quality, noise, climate change and economic growth. Any expansion must meet all four to proceed.

Heathrow has separately approved work on its own planning application, describing the moment as a significant milestone as a series of 2026 decision points approach. The airport's blueprint envisages a £49bn expansion that would lift annual capacity by around half.

What the plans involve

Heathrow's proposal centres on a new 3,500-metre north-western runway, a new terminal known as T5X, three additional satellite terminals and substantial upgrades to existing facilities. Together these would allow the airport to handle up to 150 million passengers a year and as many as 756,000 flights.

The airport argues that the expansion is essential to keep Britain competitive as a global hub and to support trade and connectivity. Critics counter that it is incompatible with the country's climate commitments and would impose intolerable noise and air pollution on surrounding communities.

Heathrow says expansion would create tens of thousands of jobs and unlock billions of pounds of investment, framing the project as a test of whether Britain can still deliver nationally significant infrastructure. Surface access is a central part of the debate, with the airport under pressure to show that extra passengers can be carried by rail and public transport rather than adding to the congestion already choking the surrounding road network.

• Draft national policy statement published, with consultation open until 1 September.
• Four tests to be met: air quality, noise, climate change and economic growth.
• Proposed new 3,500m north-western runway and a new T5X terminal.
• Capacity to rise to up to 150 million passengers and 756,000 flights a year.
• Headline cost of the expansion put at around £49bn.

Timetable and rival schemes

The Government has set out a timetable that would see planning permission secured by 2029 and a third runway in operation within around a decade. That schedule leaves little room for slippage given the scale and complexity of the works involved.

Heathrow's own proposal is not the only one on the table. A rival scheme from the Arora Group and Heathrow West has put forward a two-phase approach to building the new runway, offering an alternative to the airport's full-scale plan and adding a further layer of complexity to the decision.

“This is the most significant moment for Heathrow expansion in a generation. A third runway is vital for growth, jobs and Britain's place in the world, and we are determined to deliver it responsibly.”

Opposition and environmental concerns

Environmental campaigners, local residents and a number of councils remain firmly opposed, warning that a bigger Heathrow would undermine legally binding climate targets and worsen noise and air quality for hundreds of thousands of people living under the flight paths.

They argue that the four tests set out by the Government are stringent for good reason, and that any honest assessment will struggle to reconcile a major increase in flights with the UK's emissions obligations.

“You cannot expand the country's biggest airport and still claim to be serious about the climate. This consultation must be a genuine test of the evidence, not a rubber stamp for a decision already taken.”

Background

The case for a third runway at Heathrow has been debated for decades, with successive governments commissioning reviews, granting and withdrawing support, and facing legal challenges along the way. The airport operates close to its capacity limits, and proponents say expansion is the only way to relieve the pressure and maintain its hub status.

The latest consultation revives the question in earnest, setting up a months-long process that will draw fierce argument from all sides.

What happens next: responses to the consultation will be assessed before ministers decide whether to designate the national policy statement, which would set the framework for any formal planning application. With the Government targeting permission by 2029, the coming year will be decisive in determining whether the third runway finally takes flight.