Heathrow expansion: Government accelerates review to deliver third runway by 2035
October 23, 2025
Plans to expand Heathrow Airport are being “accelerated” by the UK government, paving the way for work to begin as soon as 2029 and the first flights to take off by the middle of the next decade.
Ministers are launching a fast-tracked review of the Airports National Policy Statement (ANPS) that could clear the way for the construction of a third runway before the end of the current parliament.
Government seeks to fast-track Heathrow expansion
A decision will be made on which company will lead the project by next month, with the government keen to avoid delays which had dogged any attempt to expand slot-constrained Heathrow in recent years.
Transport Secretary Heidi Alexander told MPs on 22 October that the review will be completed three years faster than the original process in 2018.
The government has pledged to deliver “swift but robust” progress, describing Heathrow’s expansion as a key test of the government’s pro-growth agenda.
Chancellor Rachel Reeves said that after “decades of false starts, we are backing the builders to get Heathrow’s third runway built”.
The updated policy statement will set the framework for evaluating any expansion proposals, reflecting new environmental and climate obligations introduced since 2018.
The Department for Transport (DfT) said the review will examine four core tests for any Heathrow scheme: compatibility with climate change targets, controls on noise and air quality, and the project’s contribution to UK-wide economic growth.
Officials expect a draft version of the revised ANPS to go out for consultation by summer 2026.
The government aims to complete the process in time for a final planning decision within this parliamentary term.
That would keep open the goal of seeing aircraft depart from a new runway in west London by 2035.
The review represents the most significant step toward Heathrow expansion since the original ANPS was approved in 2018.
Who will design and manage the third runway project?
There are now just two contenders – Heathrow Airport Limited (HAL) and the Arora Group – to deliver the project following a call for proposals earlier this year.
Key features of HAL’s expansion plan
- The scheme centres on the construction of a new third runway, approximately 3,500 metres long, located to the north-west of the existing runways.
- The plan envisions raising the airport’s annual capacity to around 150 million passengers per year.
- A major element is the realignment of the M25 motorway between Junctions 14 and 15 – with a new section built west of the existing carriageway to accommodate the runway intersection with minimal disruption.
- A new terminal complex, labelled “T5X”, is part of the package – west of Terminal 5 – together with redevelopment and extensions of the existing terminals (including Terminal 2 and the closure or replacement of Terminal 3 in earlier proposals).
- The expansion also includes revamped cargo facilities, taxiways and airfield infrastructure, and upgraded surface access links (road, rail and parking).
A competing submission from Arora Group offers a different approach, suggesting a potentially cheaper and phased alternative that it claims would deliver similar capacity improvements with less disruption.
Arora has previously positioned itself as a challenger to Heathrow’s monopoly, arguing that competition in infrastructure delivery would yield better value for passengers and airlines.
Its “Heathrow West” plan has been developed alongside Bechtel and avoids the need to build over the M25.
Arora Group’s “Heathrow West” alternative proposal
- Arora proposes a 2,800-metre third runway, significantly shorter than the approx. 3,500-metre runway in the plan advanced by Heathrow Airport Ltd (HAL). By opting for the shorter runway, Arora aims to avoid the disruptive and expensive requirement to reroute the M25 motorway. The target operational date for the runway is also around 2035.
- In conjunction with the runway, the Arora plan calls for a new terminal complex (often referred to as a “Western Hub” or “Terminal 6”) to be delivered in phased form — first opening around 2036, with full completion by 2040
- The scheme is presented as a more cost-efficient alternative to HAL’s broader masterplan. Arora claims savings of several billion pounds via structural and design efficiencies: for example, removing or simplifying certain terminal expansions, transport systems and avoiding the motorway diversion project
Both have been asked to provide further information on their designs, impacts, and investment plans before a preferred scheme is selected in November.
Any expansion will be privately financed, with no cost to taxpayers, and will be subject to strict cost controls.
The government has stressed that it is for either HAL or Aurora to choose when to bring forward an application for development consent.
‘Critical building block’ towards third runway
Alexander said, “When we say this government is one that backs the builders, not blockers, we mean it.
“Today is a critical building block which will advance plans for the delivery of a third runway at Heathrow, meaning people can start to experience the full benefits sooner.
“As our only hub airport, Heathrow is critical to the UK’s economy, connecting millions of people every year and exporting British businesses across the globe.
“Enabling Heathrow expansion will drive economic growth and create jobs across the country, delivering on our Plan for Change.”
The announcement follows government approvals for the expansion of Luton earlier this year and Gatwick last month.
Industry groups have welcomed the renewed commitment to expansion.
AirportsUK chief executive Karen Dee said clear policy direction was vital to attracting investment, while Airlines UK chief executive Tim Alderslade said any scheme “must be affordable, deliverable and aligned with the industry’s net zero commitments, principally through the scale-up of advanced SAF and a modernised UK airspace.”
