A party held on a train serving the Circle Line on the London Underground. Because Circle Line trains travel in a continuous loop, a party once begun on a train can continue indefinitely until the Underground
shuts down for the night. Circle Line parties (or CLPs) are usually scheduled in advance and in recent years have been publicised via the Internet. The first CLP is thought to have been organised by an anarchic group called the Space Hijackers on 10 March 1999.
Permission is not sought from London Underground or the British Transport Police for the parties. Parties have typically included drinking, playing music and pole dancing. Until 2008, none of these activites was banned on the Underground; however police have broken up parties in the past.
The future of Circle Line parties is uncertain as drinking alcohol on the Underground (and other public transport in London) was banned by London mayor Boris Johnson with effect from 1 June 2008. To commemorate the event, a Circle Line party was held on the evening of May 31. The event attracted several thousand partygoers, was overwhelmingly good-natured and only about 17 people were arrested. However, police broke up the parties before the deadline of midnight.
"We are not organising the Circle Line party, you are! You are the entertainment, you are the acts, you are the crowd, you are the life and soul." - From Space Hijackers website, organisers of Circle Line parties