Heathrow bosses on Monday defended their response to a fire that shut down Europe’s busiest air hub for almost a day, after Britain's energy system operator suggested the airport had enough electricity from other sources to keep running.

Britain's Heathrow defended its decision to shut down operations at Europe's busiest airport last Friday as the blame game intensified over an 18-hour closure which cost airlines tens of millions of pounds and stranded thousands of passengers.

The blaze forced Britain’s largest airport to cancel or divert more than 1,000 flights on Friday and removed a linchpin of global air travel. Counterterrorism police were investigating the cause of the fire.