London Mayor Opposes Heathrow Airport Expansion Plans

The London mayor has formally opposed plans for a third runway at Heathrow Airport, citing concerns over environmental targets and transport networks. City Hall and Transport for London (TfL) submitted a joint response to the government's draft Heathrow Expansion National Policy Statement (HENPS) consultation. Mayor Sir Sadiq Khan stated that the strategic case for the expansion relies on outdated evidence that does not reflect current climate laws and travel habits. The government is reviewing the response, while Heathrow Airport has questioned many of the claims made in City Hall's submission, asserting that the expansion represents a significant economic growth opportunity for the UK. Sir Sadiq Khan expressed skepticism about the compatibility of the proposals with a credible path to net zero, stating, "The evidence suggests Heathrow expansion is a risk that we simply cannot afford to take." City Hall indicated that additional flights could reverse progress made in reducing air pollution in surrounding communities due to the Ultra Low Emission Zone (Ulez). The submission raised concerns about infrastructure and financial implications, with TfL estimating that targets in the draft policy could lead to 60,000 additional daily highway trips, resulting in 22 million extra road journeys annually on the M4 and M25. Capacity upgrades would be necessary for the Elizabeth and Piccadilly lines, along with new rail links, with potential surface access costs estimated at £9 billion. TfL also noted that a 58% increase in flights would reduce predictable noise respite periods for local residents from 50% to 25% of the day. Sir Sadiq Khan reiterated his opposition to the expansion, stating, "I will continue to vehemently oppose these plans as I seek to build a fairer, safer, greener, more prosperous London for everyone." Heathrow Airport Limited is preparing plans for a new 2.1 mile (3.5 km) northwest runway, which would require realigning a section of the M25, with a final decision expected following a parliamentary vote in 2029. The airport has rejected claims that the expansion is incompatible with net zero goals and emphasized its commitment to a privately-funded noise insulation scheme for local homes. Heathrow stated that its expansion plans include widening a busy stretch of the M25 and will present viable and funded solutions for necessary public transport upgrades. The mayor's stance is supported by a coalition of council leaders from London and surrounding counties, who have called on the government to withdraw support for the third runway. However, the Back Heathrow campaign argues that the opposition from councils does not represent local residents, claiming that over 100,000 local members support the expansion due to its potential for job creation and economic growth. The Department for Transport, which supported expansion under Keir Starmer's premiership in 2025, stated that ministers would carefully consider all responses before outlining next steps later this year, emphasizing that expansion will only proceed if it aligns with legally binding climate change obligations and meets strict environmental standards.