England footballers, Doctor Who's David Tennant and Oasis are among stars aiming to help Comic Relief raise more than £40 million on Friday.
Members of the England team including David Beckham and Frank Lampard took part in a comedy sketch with Gavin and Stacey actor James Corden while Dawn French and Jennifer Saunders have filmed a spoof version of Mamma Mia! for the BBC1 fundraising broadcast.
Oasis are among a host of musical acts set to perform on the show, with Take That, Franz Ferdinand, James Morrison, Elbow, the Script and Annie Lennox all part of the lineup.
The Saturdays will perform their number two Comic Relief single Just Can't Get Enough while Corden's Gavin and Stacey co-stars Rob Brydon and Ruth Jones will be joined by Tom Jones for a rendition of their single (Barry) Islands in the Stream.
Robbie Williams has joined Little Britain's Matt Lucas and David Walliams for a comedy segment, with other sketches set to include The Royle Family, Harry Hill's TV Burp and Ricky Gervais.
A documentary following a group of nine celebrities - including Gary Barlow, Cheryl Cole and Chris Moyles - reaching the summit of 6,000 foot African peak Kilimanjaro was screened on Thursday night on BBC1, with £1.5 million raised for Comic Relief.
The group met the prime minister on Thursday, with Gordon Brown telling them they were "inspiring a generation of kids who would never have thought about these things" and were "nine heroes".
Organisers hope this year's Comic Relief will surpass the record £40 million raised in 2007.