ITV News Correspondent Dan Rivers is at Heathrow, where passengers have complained of long waits and a lack of social distancing
The Home Office has admitted that long queues at Heathrow immigration checks have been "unacceptable," amid criticism from travellers and the airport itself.
Throughout the week passengers have shared footage of crowded scenes at Border Control, complaining of long waits and a lack of social distancing.
The airport said Border Force, which manages the checkpoint at Heathrow, knew there would be extra demand and said they were "very disappointed" at a lack of staff.
One passenger said she'd been warned to expect a two hour wait to pass through immigration after landing at the airport.
On Saturday afternoon, a Heathrow spokeswoman said: "We are very sorry that passengers faced unacceptable queueing times in immigration last night due to too few Border Force officers on duty.
"Border Force were aware of the extra demand from families and we were very disappointed that they did not provide sufficient resource.
"Additional Heathrow colleagues supported in managing queues and handed 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 said: "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.
"This is the busiest weekend of the year for returning passengers, with particularly high numbers of families with children under the age of 12 who cannot use e-gates.
"Border Force is rapidly reviewing its rosters and capacity and flexibly deploying our staff across the airport to improve waiting times.
"We are working very closely with Heathrow Airport and its airlines and we are all committed to making sure all passengers can have a safe and hassle-free journey.”