Heathrow warns Istanbul may eclipse its European crown

Heathrow’s chief executive has acknowledged that Istanbul Airport is poised to overtake the London hub as Europe’s busiest airport, intensifying pressure on the UK’s long-debated expansion plans. Thomas Woldbye told journalists that capacity constraints at Heathrow, coupled with Istanbul’s rapid growth and multi-runway architecture, were shaping a shift in continental air traffic rankings that could materialise as early as 2026 or 2027. This development forms a central plank of Heathrow’s argument for building a third runway, a project that has been delayed by political wrangling for decades.

Traffic figures for 2025 show Heathrow handling about 84.46 million passengers, narrowly ahead of Istanbul’s approximately 84.46 million. Data compiled by industry analysts indicates the gap has all but closed, with Istanbul increasing its passenger numbers by around 5 per cent year-on-year compared with a modest 0.7 per cent rise at Heathrow. The trend reflects Istanbul’s ability to expand capacity unconstrained by slot limits and runway availability that increasingly bite at Heathrow.

Heathrow operates with two runways near full capacity, whereas Istanbul benefits from five runways and significant spare capacity to handle growth, giving it a structural advantage in attracting airlines and passengers alike. Aviation economists point out that hub airports with greater runway and terminal capacity can support more flight movements and connections, reinforcing their roles as global transit points. The momentum behind Istanbul’s expansion has seen it surpass other major European hubs such as Amsterdam Schiphol and Paris Charles de Gaulle in passenger throughput, underscoring its emergence as a dominant aviation centre.

Woldbye framed the looming loss of the busiest airport title not as an isolated statistic but as evidence of broader capacity challenges that Heathrow must confront. He reiterated that the third runway project, which received government backing in principle last year, remains crucial to sustaining the airport’s competitive standing and supporting broader economic objectives. The scheme, which could cost up to £49 billion including additional terminals and infrastructure, requires a regulatory and investment framework that attracts capital from Heathrow’s international shareholders, including sovereign wealth funds.

Government and industry sources confirm that steps toward planning approval are underway, with final consent for the new runway targeted by 2029 and initial flights from the expanded facility anticipated as early as 2035. Woldbye said the UK government’s stated commitment to economic growth gives him confidence the project will advance, even as critics question whether the political will remains strong enough to see it through.

Critics of the expansion argue that rising costs, environmental concerns and the spectre of regulatory hurdles could yet delay or derail the project. Opponents, including environmental campaigners and some community groups, have warned that the financial burden on taxpayers could balloon if expected investment does not materialise or if unforeseen legal challenges arise. Heathrow’s own debt profile, which climbed significantly in the past five years, adds another layer of scrutiny to the project’s risk profile.

Airline industry sources note that Heathrow’s appeal remains strong with carriers that value its extensive route network and slot connectivity. British Airways and Virgin Atlantic, for example, continue to operate significant long-haul schedules from the airport, and Heathrow is still seen as a gateway to North America and Asia for many global travellers. These airlines have expressed support for expansion while urging regulators to ensure that passenger costs and operational efficiency are balanced against investment returns.

Passengers have also shown resilience in demand for Heathrow services. The airport reported an all-time high of more than eight million passengers in a single month last year, with improved punctuality and baggage performance contributing to a more reliable traveller experience. Such operational milestones reinforce Heathrow’s role as a major international hub even as it grapples with growth constraints.

Industry analysts say the ongoing competition between Heathrow and Istanbul is part of a broader rebalancing of air travel in Europe. Factors include geography, airline network strategies, and investment climates that influence airline and passenger choices. While Heathrow’s deep connections and legacy status have underpinned its leadership for many years, Istanbul’s strategic position between continents and its capacity to scale have accelerated its challenge for the top spot in European aviation.