TV legend Terry Wogan, supermodel Elle Macpherson and Strictly Come Dancing winner Louis Smith are some of the stars who will be helping Graham Norton's bid to break the world record for the most questions asked on a TV chat show, while also raising funds for charity.

Comic Relief's Big Chat with Graham Norton will be broadcast on BBC Three on Thursday March 7 and will run for at least six hours as Norton tries to set a new Guinness World Record.

Among the other stars confirmed are: Kirstie Allsopp, Heston Blumenthal, Jimmy Carr, Ronnie Corbett, Martin Freeman, Nick Grimshaw, Sarah Millican, James Nesbitt and Frank Skinner, with music on the night set to be provided by Example, Paloma Faith and Laura Mvula.

Norton said: "David Walliams swam the Thames, John Bishop endured a week of hell and Eddie Izzard ran marathon after marathon after marathon.

"I am hoping to join this elite group of celebrity fundraisers by doing what I do best - sitting on my backside and talking."