A recent Department for Transport report evaluating the proposed expansion of Heathrow Airport has concluded that the project carries a substantial negative economic value. The appraisal, which assessed the construction of a new 3,500-metre runway, a sixth terminal, and associated infrastructure, estimates the net present value (NPV) of the scheme to range between minus £23.4 billion and minus £62.5 billion over a 60-year period. This negative NPV indicates that the social costs of the expansion—including environmental impacts such as increased carbon emissions, noise, and air quality degradation—would outweigh the projected economic and passenger benefits.

The figures, derived using Treasury Green Book guidelines for infrastructure assessment, demonstrate that the higher negative figure assumes costs would be passed on to passengers and that both departing and arriving flights contribute to carbon limits. The report concludes that the country would benefit more by foregoing the project altogether.

A secondary analysis conducted by Frontier Economics, commissioned by the government but employing a different methodology, further questions the expansion’s economic impact. This study dramatically lowers the estimated contribution to GDP growth to just 0.053 percent in a best-case scenario—significantly below the figures previously promoted by Heathrow Airport and Labour’s shadow chancellor, Rachel Reeves. Reeves has claimed the expansion would generate up to £42 billion in benefits and support more than 60,000 local jobs, but the DfT report suggests these figures focus exclusively on benefits while neglecting offsetting costs.

Andy Burnham, the former Greater Manchester mayor and Labour leadership contender, has expressed longstanding reservations about the plan. He argues that Heathrow’s expansion would concentrate infrastructure investment in London and the southeast, undermining regional development and economic rebalancing efforts. Burnham’s position aligns with findings from the appraisal report, which warns that the expansion could reinforce Heathrow’s monopoly, siphoning traffic and revenue away from other UK airports and drawing firms and workers toward already productive areas rather than dispersing opportunity nationwide.

Furthermore, the report notes that the anticipated employment growth at Heathrow would primarily reflect a redistribution of the existing labor force rather than net job creation across the country, a point that complicates assertions of widespread economic benefit.

Responding to the report, a spokesperson for the Department for Transport emphasized that the NPV is only one element of the broader evaluation framework while reiterating key claims made by Reeves. Heathrow Airport officials defended the project, contending that the appraisal underestimates passenger demand and fails to consider potential growth in air cargo, highlighting that the airport handled £293 billion worth of goods last year. The airport also argued that it is inappropriate to deduct construction costs from benefits given that the expansion is planned as a privately financed investment, unlike publicly funded infrastructure projects such as the proposed HS2 extension to Manchester favored by Burnham.

Despite these rebuttals, the newly published government analysis presents a formidable challenge to supporters of the Heathrow expansion, suggesting that even official metrics do not support the case for proceeding with the runway development.