Hundreds of Londoners stripped off to celebrate the 10th annual “No Trousers Tube Ride” - and banish people’s January blues.
Tom Hayes, one of the brave souls who journeyed in his pants on Sunday, estimated at least 500 people took part as they split into four groups.
The capital’s No Trousers Tube Ride originates from the “No Pants Subway Ride”, which began as a small prank in New York in 2002 but has since spread to over 60 cities worldwide.
In London on Sunday, it started at the National Gallery, with people arriving in full clothing before following the signal to strip off and take to the Tube stations.
Mr Hayes, a former organiser of the event, told the Standard: “It’s basically an international day of silliness. January is a depressing, boring month. So what better way to have fun and make people laugh than go on the Tube in your pants?
“It’s open to everyone – regardless of their age, gender or body size – and we split into four groups.”
He added: “It’s always a little tense to begin with, with everyone working out which point do they get undressed.
“But we always have a laugh. It’s just a really jovial, welcoming, friendly atmosphere.
“There was even one person who hadn’t been taking part, but then saw us and joined in!”
The No Trousers Tube Riders will be rewarded for their efforts with an after-party at Soho’s Chandos pub.