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?
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More than a tenth of the Piccadilly Line train fleet is out of action because of emergency repairs to damaged wheels.
Rows of students stood and turned their backs before filing out of the lecture theatre.
Effie the endangered Western lowland gorilla has given birth to a healthy baby boy at London Zoo.