Staff are struggling to cope with queues to check passports at Heathrow Airport, the BBC reports.
Personnel are said to have been redeployed from English Channel ports to help airport colleagues deal with delays.
An unnamed member of south-east Border Force staff told the BBC: “We are being crucified. There is a high percentage of long-term sick due to stress. We are being pushed completely and we cannot cope.”
The whistle-blower reportedly said staff were not given sufficient time to examine passports properly. He claimed some Border Force staff had to start their shift at Dover, drive to Heathrow to do three hours’ airport work, then drive back, according to the BBC.
An aim for Border Force to process 95 per cent of those from outside the European Economic Area within 45 minutes was not met in the four terminals in June. The proportions cleared within the target time were 89.4 per cent, 91.3 per cent, 93.3 per cent and 94.1 per cent in terminals two, three, four and five respectively.
MP Keith Vaz, chairman of the Home Affairs committee, said: “During the peak summer months there is always an increase in passenger numbers. “It is a no-brainer for those who run Border Force to have made contingency plans to increase staffing levels for this period. Rather than deploying officers from policing border security issues additional staff should have been drafted in to deal with passport checks at Heathrow.”