Heathrow and the Government were warned a decade ago that the airport was overly reliant on very few sources of power to keep it fully functioning, it has emerged.

A report by a global planning and infrastructure consultancy identified “the key weakness” to the airport’s ability to operate as being its dependence on “the main transmission line connections” from the National Grid.

These are just three electricity substations, or “grid supply points”, which cannot replace each other without lengthy reconfiguration.

When the North Hyde substation in Hayes exploded and went up in flames at 11.20pm on Thursday, it plunged the entire airport into chaos, forcing the diversion and cancellation of thousands of flights and leaving tens of thousands of passengers stranded.

It was precisely the nightmare scenario predicted in a report by Jacobs consultants in 2014 when it assessed the operational risks faced by Europe’s busiest international hub.

As Heathrow’s operations began to return to normal following its reopening on Friday night, its chief executive blamed the external power failure and said similar disruption could happen at other airports.

Thomas Woldbye said he was “personally quite proud” of how quickly the airport responded to the power outage that brought all flights to a halt.

He added: “This situation was not created at Heathrow Airport. It was created outside the airport and we had to deal with the consequences.”