Previously announced to be taking part in this week's comedy fundraiser were Lulu, Noel Fielding, Penny Smith and Andi Osho. It has now been revealed that they will be joined by comic Jarred Christmas and a double act featuring Emmerdale's James Thornton and comedian Charlie Baker.
McFly will perform on this weekend's show, while Lee Mack, Jack Whitehall and Keith Lemon are on the judging panel.
The final heat will feature performances from Caroline Flack and Joe Swash, comics Adrian Edmondson, Marcus Brigstocke and Lee Nelson and popstars Toyah Willcox, Clare Grogan, Chesney Hawkes and Limahl.
Judging the third programme will be John Bishop, Felix Dexter and Jo Brand, while Jessie J and The Wanted will perform in the studio.
Let's Dance... airs on Saturday at 7pm on BBC One.