Thousands of travellers packed into the west London airport on Friday, with reports of people waiting several hours to get through passport controls. The Home Office, which is responsible for Border Force, has admitted the situation is “unacceptable” and promised action.

Friday night saw the worst scenes, with reports of passengers being taken ill during the queue.

Photographs posted on social media showed large number of people crammed together, despite the coronavirus pandemic.

A number of travellers expressed their frustration on Twitter and other social media sites.

One wrote: “There are people collapsing in Terminal 5 Arrivals due to overcrowding and no ventilation. Some Covid secure measures.”

A second commented: “Horrendous kettling at Heathrow Terminal 5 arrivals tonight.

“No Border Force. No ventilation. No fire exits. No explanation.

“Held there for over an hour. People fainting. Panicked skeleton Heathrow ground team not knowing what to do.”

Another added: “Wow never seen anything like Heathrow right now for passport control.

READ MORE: UK tourism arrivals plummet as Heathrow staffing chaos continues

There are a particularly high proportion of children under-12, who take longer to process as they can’t use e-gates.

Heathrow said it had “escalated” the problem with Border Force, who it asked to provide additional resources.

A spokesperson for the airport said: “We are very sorry that passengers faced unacceptable queuing times in immigration due to too few Border Force officers on duty.

“Border Force were aware of the extra demand from families and we are very disappointed that they did not provide sufficient resource.

“We have additional Heathrow colleagues to support in managing queues and to hand out passenger welfare including water, but we need every immigration desk to be staffed at peak times.

“We have escalated this with Border Force and expect them to provide a better service over the remainder of the weekend.”

A Home Office spokesman branded the situation “unacceptable”, and promised action would be taken.

He commented: “Throughout the pandemic we have been clear that queue times may be longer as we ensure all passengers are compliant with the health measures put in place to keep the UK public safe. However, the very long wait times we saw at Heathrow last night are unacceptable.

“Border Force is rapidly reviewing its rosters and capacity and flexibly deploying our staff across the airport to improve waiting times.

“The Home Office added that Border Force was working closely with Heathrow Airport and its airlines and was committed to ensuring passengers had “a safe and hassle-free journey.”