Tennis player Jamie Murray - the brother of British number one Andy Murray - was caught up in the queues at passport control on Thursday night.
He tweeted these pictures, estimating that there must be a couple of thousand people waiting in line.
He added the hashtag #thirdrunwayanyone?
More top news
Detectives have released a CCTV image as they hunt for man who sexually assaulted woman at bus stop in east London.
Shops and restaurants on the route of the Notting Hill Carnival have boarded up as shop-keepers and residents aim to protect their property.
Bank Holiday rail disruptions mean many of London's trains have ground to a halt this weekend, meaning options beyond the tube are limited.