People taking part in next weekend's Notting Hill Carnival are displaying their flamboyant costumes at Alexandra Palace in north London.
Each participant performs a two-minute dance routine at the Grand Costume Splash, when the titles of carnival "king" and "queen" are awarded.
Spokeswoman Gloria Cummings said the contest was a relaxed public event but participants were "on tenterhooks".
About 1.5 million people are expected at the annual west London street party.
Prizes are also awarded for the best male and female costumes.
Ms Cummings said: "The purveyors of the art form are on tenterhooks because they are trying to get everything ready so it looks good on the stage, and they still have to plan for next weekend."
Police hoping to pre-empt trouble at this year's carnival made eight arrests on Thursday after drug searches at homes in Battersea, Ealing, Tottenham and Southwark.
Almost 150 letters have been sent to known troublemakers across the capital warning them not to attend the event.