Heathrow has said its project to build a third runway has been delayed by “at least 12 months” after the aviation regulator rejected its spending plans.
The Civil Aviation Authority (CAA) has refused Heathrow’s request to lift spending from £650m to £2.4bn before it even gets planning consent.
The CAA is concerned passengers will end up shouldering the cost if Heathrow does not win permission to expand.
The airport now expects to complete a third runway between 2028 and 2029.
In a consultation published by the CAA, it said “the best approach in the interest of consumers” is to limit certain early construction costs to £1.6bn.
The consultation also said an assessment by an independent fund surveyor of Heathrow’s plan to open a new runway by 2026 was an “aggressive schedule” which would require “maximum activity” even before the airport knew whether it had been granted a development consent order.