Andy Burnham backs Heathrow third runway expansion in major U-turn

Prime Minister Andy Burnham has executed a significant political shift, as his government gives the green go-ahead to revive plans for a third runway at Heathrow Airport. The reversal marks a stark departure from the prime minister's long-held stance during his tenure as mayor of Manchester, where he repeatedly campaigned against the aviation project over regional funding disparities.

Speaking in the House of Commons on Tuesday, 8 September 2026, Chancellor John Healey formally announced that the administration was moving forward with the controversial airport development, according to reporting by the Express and the Daily Mail. Healey defended the pivot by telling MPs that the administration gave the project the green light simply because the economic case stacks up and will help bring growth after years of delay, indecision, and vexatious challenge.

Media additions

The policy shift stands in sharp contrast to Burnham's historical opposition. As Manchester mayor, Burnham warned that expanding the UK's largest airport would divert vital infrastructure investment away from the North and trap it inside London. In January last year, he branded the scheme a model for an ever-overheating UK economy and previously argued in 2018 that the nation needed to limit national levels of aviation by utilizing spare capacity at airports in Manchester and Birmingham instead.

The runway expansion plan carries an estimated total cost of £33 billion. This figure incorporates a £1.5 billion price tag to physically move a section of the M25 motorway to accommodate the new strip, though project backers maintain the entire undertaking will be fully privately financed. Once completed, the west London hub—which was surpassed by Istanbul as Europe's busiest airport in July—would see its operational capacity surge to 756,000 flights and 150 million passengers every year.

Proponents of the expansion argue that the infrastructure is vital to keep the country competitive. Representatives for Heathrow stated that the airport is currently operating at capacity and that the project will deliver essential economic growth. Former Chancellor Rachel Reeves, who championed the project before leaving her post, previously described the scheme as critical to national growth, a sentiment echoed by airport officials who say the country urgently requires the infrastructure.

However, the U-turn has immediately reignited intense political and environmental rows. Questioning the Chancellor in Parliament, Liberal Democrat business spokesperson Sarah Olney branded the initiative an absurd proposal. She highlighted official government appraisal reports suggesting the net present value of the expansion could range from minus £23.4 billion to minus £62.5 billion. Sadiq Khan, the Mayor of London, also condemned the plans, pointing to detrimental impacts on local air quality, noise pollution, the wider environment, and surrounding transport networks.

The Heathrow announcement arrives amid a broader wave of economic and industrial strategy reassessments across Whitehall. As detailed in our politics coverage, the new administration is navigating complex trade-offs on energy, taxation, and regional development. Similar pragmatic policy pivots have surfaced elsewhere in the energy sector, where figures like green energy tycoon Dale Vince have controversially backed controversial North Sea drilling projects such as Rosebank and Jackdaw to secure cheaper wholesale energy, mirroring reported deliberations by Energy Secretary Ed Miliband to calm financial markets.

For Burnham, the Heathrow reversal risks alienating northern voters and local leaders who trusted his past commitments to rebalance infrastructure spending away from the capital.

Project Metric	Projected Figure
Total Estimated Scheme Cost	£33 billion
Cost to Move the M25	£1.5 billion
Target Annual Passenger Capacity	150 million
Target Annual Flight Capacity	756,000

What Happens Next

Public consultations and regulatory hurdles for major national infrastructure projects continue to face strict scrutiny from environmental campaigners and local authorities. Attention now turns to upcoming parliamentary debates over regional funding guarantees and how the administration plans to balance its renewed backing for south-east aviation growth against persistent demands for northern transport investment.