The airport had been due to handle 1,351 flights on Friday, flying up to 291,000 passengers, but planes were diverted to other airports in Britain and across Europe, while many long-haul flights returned to their point of departure.

The industry is now facing the prospect of a financial hit costing tens of millions of pounds, and a likely fight over who should pay.

Airlines including JetBlue, American Airlines, Air Canada, Air India, Delta Air Lines, Qantas, United Airlines, IAG-owned British Airways and Virgin were diverted or returned to their origin airports in the middle of the night, according to data from flight analytics firm Cirium.

‘Huge impact’ on customers

Airline executives, electrical engineers and passengers questioned how Britain’s gateway to the world could be forced to close by one fire, however large.

‘Wake-up call’

Prime Minister Keir Starmer’s spokesperson said there were questions to answer about how the incident occurred and there would be a thorough investigation.