Ricky Gervais has revealed his new BBC sitcom Extras was a "logistical nightmare" to shoot - because of his celebrity guest stars' busy schedules.
By Neil Smith
BBC News entertainment reporter
"I really can't believe we got away with it," he told reporters at the press launch for the series, which begins on BBC Two on 21 July.
Ricky Gervais and Stephen Merchant both write and star
"It's bad enough trying to get everything co-ordinated with new actors.
"But when you've got people for one day who might be in the middle of a film on the other side of the world, it's amazing we pulled it off."
Gervais stars as Andy Millman, a bit-part actor who finds himself looking on from the sidelines in a series of large-budget productions involving high-profile stars.
Samuel L Jackson, Kate Winslet and Patrick Stewart are a few of the big names involved, alongside British TV regulars Les Dennis and Ross Kemp.
The series opens with Hollywood actor Ben Stiller spoofing himself as an egotistical director trying to make a serious drama about the war in Bosnia.
"When we sent Ben the rough idea, he sent me an e-mail saying I'd tapped into his very soul," said Gervais.
"But he isn't like that at all. In fact he's very erudite and quite a quiet character."
"He was fantastic - he flew over from LA and it rained for two days. It was a great introduction to working in Britain."
Gervais and his writing partner Stephen Merchant approached a number of celebrities to see if they would be interested in taking cameo roles.
But fame and international standing were not the only criteria.
"They needed a certain amount of baggage we could play with," said Merchant, who appears in the series himself as a hapless agent.
Samuel L Jackson (l) and Ross Kemp (r) also appear
"We wanted people who would bring a certain weight to it," added Gervais.
"We paid them, but let me tell you - they certainly didn't do it for the money."
Comparisons to hit sitcom The Office are inevitable, though both Gervais and Merchant are keen to play down similarities to their previous show - a critical and ratings hit.
"There's nothing connecting it apart from us writing it and me using these facial muscles," said Gervais.
"We will get compared to The Office, but I hope people watch it without prejudice."
According to the actor, Andy Millman is much closer to his own personality than that of Office tyrant David Brent.
"He's much more a person you can identify with, though he does have his own issues and neuroses."
A second series is on the cards, with Gervais enlisting both Madonna and Brad Pitt at London's Live 8 concert.
Ben Stiller (l) is the first episode's celebrity guest
"Brad came up to me and said he loved The Office, so I asked if he wanted to be in Extras," said Gervais. "He said, 'Call me.'
But Merchant added: "I don't think that counts as a yes. I think he was just being polite."
Pitt or no Pitt, the pair have plenty of ideas for Andy and his hapless fellow extra Maggie - played by relative newcomer Ashley Jenson.
"There was a theme in The Office, about desperation for fame, which we're fascinated with," says Gervais.
"We don't really know what it's like to be an extra," laughs Merchant. "We're just using it as an excuse to have some fun in that world."