Passengers flying into the UK are facing long delays at passport controls as e-gates across the country have gone down.
The issue is affecting people arriving at UK airports, the Home Office said, after the system went down on Friday night.
One passenger arriving at Gatwick said the situation was an “utter joke”.
Lucy Morton, from the Immigration Services Union, warned that queues would build “very, very quickly”.
“You end up putting all the passengers through physically-manned officer desks,” she told the BBC’s Radio 4.
She said between 60-80% of travelling passengers will go through e-gates, depending on the airport.
“There’s no impact on national security,” she said, explaining that all arrivals will still be fully checked.
“But it will build queues and that in itself builds its own set of problems. People becomes frustrated, they take it out on the staff. All of this will cascade during the day.”
All airports across the country that use the gates are affected, meaning people flying in are having to queue to get their passports checked manually.
The e-gate system speeds up passport control by allowing some passengers to scan their own passports. The system uses facial recognition to verify a traveller’s identity and captures an image of the traveller as they pass through the gate.
E-gates can be used by British citizens aged over 12 and those from the EU, as well as people from several other countries including Australia, Canada, the US, Japan and New Zealand.
But all entry points retain manned security desks for other passengers and those who are unable to use the e-gates.
A Home Office spokesperson said they were aware of a “nationwide border system issue affecting arrivals into the UK”.
“We are working to resolve the issue as soon as possible and are liaising with port operators and airlines to minimise disruption for travellers,” they said.
Travellers leaving the UK via the Port of Dover have also faced issued after the French passport system failed earlier this morning.
The IT issue has been fixed, but cars and coaches are currently waiting for about an hour, and there are more than 400 lorries queuing to make the crossing.
This weekend was already expected to be busy for travellers, with the Bank holiday coinciding with the half-term break.
Earlier this week, British Airways was also hit by IT issues, affecting more than 20,000 passengers at Heathrow.
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