IAG questions cost of Heathrow third runway plan in evidence to UK committee

International Airlines Group (IAG), the parent company of British Airways, Iberia and Aer Lingus, has submitted written evidence to the UK Transport Committee raising concerns about the projected cost of expanding Heathrow Airport with a third runway.

The submission was among more than 70 pieces of written evidence published by the committee as part of its inquiry into the government's draft Heathrow Expansion National Policy Statement, released by the Department for Transport in mid-2026.

According to IAG, the roughly £49 billion (about $66 billion) cost estimate for the expansion is unusually high compared with other major airport projects, naming Amsterdam Schiphol, Paris Charles de Gaulle, Frankfurt and Istanbul as points of comparison. The group said it has concerns about whether the plan offers value for money and whether the cost figures presented are a reliable basis for such a significant decision.

IAG argued that independent analysis it referenced suggests Heathrow's cost evidence is selective and inconsistent, and said this undermines confidence in using it to support a major national infrastructure commitment.

The airline group emphasized that affordability is essential for the expansion to succeed, warning that without it the project could fail to deliver promised benefits such as improved connectivity, jobs, trade and investment, and could even put existing benefits at risk. IAG called on the committee to assess whether the current draft policy statement would result in an expansion that is both affordable and deliverable, stating that in its current form it does not yet meet that standard.

The Transport Committee is expected to begin hearing oral evidence on the matter starting in September 2026.