A Heathrow spokesman said:
There are some longer queues than normal in the terminals, but we have spoken to border force and they are putting on extra staff.Obviously we want to sort the issue out but not risk the integrity of the border controls.
More top news
Is your street among London's trendiest hotspots?
Some of the best stories from the past week on itv.com/london. Got a story? Email us at firstname.lastname@example.org
This is Gordon Hill. But you may know him by now as the Wealdstone Raider.