Bowie and Bloom join Gervais for new series of 'Extras'

His comic creation Andy Millman is a wannabe actor frustrated by his inability to land anything other than bit parts in movies. But in real life, Ricky Gervais has the clout to attract stars of the calibre of David Bowie and Orlando Bloom to appear in his sitcom Extras.

Coldplay's front man, Chris Martin, The Da Vinci Code star Sir Ian McKellen and the television and radio presenter Jonathan Ross will make cameo appearances in the second series of the BBC2 comedy due to air this autumn.

Thanks to the popularity of the first series, which featured guest appearances from Ben Stiller, Les Dennis, Kate Winslet and Samuel L Jackson, well-known names have been queuing up to play themselves in the sitcom.Patrick Stewart, the X-Men star, the EastEnders hardman Ross Kemp and the footballer-turned-actor Vinnie Jones also appeared in series one.

In the six-part second series, Daniel Radcliffe, the actor who played Harry Potter; Stephen Fry; the newsreader Moira Stewart; Ronnie Corbett; Germaine Greer; Richard Briers and Diana Rigg are all scheduled to appear.

Negotiations are also under way to persuade the Channel 4 chat show hosts Richard Madeley and Judy Finnigan to sign up and at least one actor from the BBC1 soap Holby City will make a guest appearance.

Filming began on Monday and Bowie has already shot his episode, in which he sings. A BBC spokeswoman confirmed the names of those who are to appear in the second series but would not comment on details of the scripts.

Gervais and his writing partner, Stephen Merchant, make frequent changes to the scripts.

The episode featuring Bowie is believed to show the rock superstar bursting into song, prompting the ejection of Millman from the VIP area of a private members' club, which he has bribed his way into.

Such is the appeal of the show that Madonna asked Gervais at last year's Live8 concert whether she could take part. But the singer had to pull out because a clash with her world tour.

It helps that Gervais is a well-known name in the US, where his hit comedy The Office won two Golden Globes and was remade for an American audience.

In each episode of the sitcom Extras, Millman turns up as an extra to the set of a different film, but despite his best efforts, speaking parts continue to elude him.

Ashley Jensen, who plays his best friend, Maggie, has won two British comedy awards for her part in the sitcom. Merchant, who only made a brief appearance in The Office, has a beefed up role as Millman's utterly useless agent.

Stars who volunteer to appear in the show have to resign themselves to being sent up. Les Dennis sportingly played himself as an actor being cuckolded by a stagehand, while Kate Winslet was happy to play herself as a foul-mouthed actress with a prurient obsession with sex.

Other story lines are believed to include Daniel Radcliffe, who plays the schoolboy wizard in the Harry Potter films, as a teenage yob and Orlando Bloom propositioning Maggie and being rejected.

Past stars

Ben Stiller

Arrogant film director making drama about the Bosnian war

Andy: Which one are you - Starsky or Hutch? I can never remember...

Ross Kemp

Mocked for hard-man image

Andy: Do you even know what SAS stands for?

RK: Special Army Soldiers...

Kate Winslet

Hard-nosed cynic obsessed with awards

KW: How many more movies do we need about the Holocaust? We get it, it was grim.

Les Dennis

Self-pitying no-hoper

LD: And while I was thinking about it [commiting suicide], Melinda Messenger came in - lovely girl, chatting away...

Andy: Took your mind off it?

LD: Yeah, I was looking at her tits.