A Home Office spokesperson has said there was “no indication of malicious cyber activity” causing last night’s incident and said “at no point was border security compromised”.

Flights are now back to normal with Heathrow Airport saying “all systems are now running as usual” and passengers “can expect to travel through Heathrow smoothly”.

Am I entitled to compensation?

Passengers won’t be able to claim compensation from their airline as this incident was beyond airlines’ control.

Some tourists may be able to claim money for taxis or airport hotels through their travel insurance.

Could this happen again?

This isn’t the first time passport e-gates have failed with a shutdown last May Bank Holiday causing widespread chaos for travellers.

Mark Flynn, IT expert at Computer Care, said: “The chaos suffered by millions of travellers last night could be just the tip of the iceberg if the Border Force doesn’t urgently evaluate its computer systems.

“The Border Force needs to regularly test its disaster recovery plans to ensure that they can quickly recover from a failure. This should include scenarios for both hardware failures and connectivity issues.”

How do passport e-gates work?

Passport e-gates check that passports are valid and that the correct traveller is using the document.

The UK’s passport e-gates can be used by a wide range of travellers including those with an EU passport or North American passport.

Gates typically take around 15 seconds to process a passport and are usually much quicker than manual checks.