Dave Hearn in TV's First Improvised Ad Break

Four comedy performers are set to improvise an advert live on TV – for a product they are only told about the moment they go on air.Henry Lewis, Jonathan Burke, Dave Hearn and Nancy Wallinger from Mischief Theatre will broadcast the commercial on Comedy Central, live from Bethnal Green Working Men’s Club.They will only be told of the mystery brand the minute the cameras are switched on at 9.10pm on Monday, during the sitcom Whitney.Watchdogs from the compliance service Clearcast will be in the club to make sure the session abides by advertising rules.The three-minute advert, filmed in front of an audience of 200, will then be edited to 30-second slots to be screened over the rest of the year.Ad agency18 Feet & Rising came up with the idea, and chief executive Jonathan Trimble said: ‘The client has put a lot of faith in us. It's a real sink or swim moment. But we have confidence that it will pay off. ‘It's a risky strategy but ballsy campaigns create big impact, and the brand feels a right fit for such an outlandish concept.’