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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His top speed is believed to be the highest ever recorded in the UK by a rider carrying a pillion passenger.
The mayor took time out from City Hall to join Conservative party workers handing out leaflets in Uxbridge and South Ruislip.
No matter where you look, London's population is getting older - with the exception of one of the capital's boroughs.