Half-term travel chaos threatened to engulf UK airports as electronic passport gates across the country failed nationwide.

All airports across the country using the gates are affected after a system crash on Friday, with passengers returning to the UK facing delays.

The issue means those flying in are having their passports checked manually.

The Home Office said it was “working hard” to resolve the issue “as quickly as possible” but could not give a timeframe amid the threat of the issue "snowballing" as half-term looms.

“We are aware of a nationwide border system issue affecting arrivals into the UK,” a spokesman said.

“We are working to resolve the issue as soon as possible and are liaising with port operators and airlines to minimise disruption for travellers.”

Border Force has “robust plans in place” to “support passenger flow and to help minimise disruption, wait times and queues” at the border, the spokesman added.

Lucy Morton from the Immigration Services Union told BBC Radio 4 that queues would build "very, very quickly".

"You end up putting all the passengers through physically-manned officer desks," she said.

"Staff can't take the breaks that they should be taking... the whole thing will snowball very quickly."

She said that between 60 and 80 per cent of passengers normally go through e-gates, depending on the airport.

The system is designed to speed up checks by using facial recognition to verify a traveller's identity as they pass through the gate.

It comes as IT issues have blighted operations at the Port of Dover for holidaymakers attempting to leave the UK after the French system to check passports failed this morning.

It has now been fixed, but will take time to clear the backlog of cars and lorries.

The issue has been compounded by the bank holiday coinciding with the half-term break.

Thousands more holidaymakers were affected by another technology failure that halted British Airways flights on Thursday.

More than 90 flights from Heathrow were cancelled and its online booking system crashed, with roughly 16,000 passengers affected.

The UK was expected to see the highest number of departures on Friday since before the pandemic, with more than 3,000 flights set to leave UK airports in one day alone.