A third runway at Heathrow is projected to cost the nation between £23.4 billion and £62.5 billion, according to figures from the Department for Transport. This analysis also concluded that the real addition to GDP would be between 0.03% and 0.05%, which is eight to 14 times less than a 0.43% figure previously claimed by Rachel Reeves when she was Chancellor, which was based on an airport-commissioned report.
The Department for Transport's analysis also weighed the social and environmental costs, indicating a net loss for the project. It found that a third runway could cause significant harm to the health and wellbeing of up to 3 million local residents.
The project has faced further delays, with Heathrow now stating that the runway would take four years longer to build than initially claimed. The estimated completion date is now 2039.
While Heathrow expansion remains official policy, Andy Burnham recently stated that the runway was "contested" and "principally it's a matter for London and London MPs."