On screen, they are the best of friends.

But as the movie inspired by their TV series premiered in London this week, the stars of Sex and the City were a bit lacking in sisterly solidarity.

Indeed, the deep-seated rivalry between Sarah Jessica Parker and some of her co-stars threatened to turn the event into a farce.

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Rivalry: Sarah Jessica Parker at the after-party (right) while Kim Cattral did not stay for the film

Miss Parker and Kim Cattrall are apparently at such loggerheads that the latter is going to great lengths to avoid any meetings.

On Sunday night Miss Cattrall apparently ordered the driver of her Audi A8 to use the staff entrance at Claridge's once she heard Miss Parker was being dropped off at the ballroom entrance.

A source said: "It's that bad. Kim can't stand her. It's no secret among those who worked on the film.

"But of course both are professional and have not let the rivalry get in the way of doing the public face of the job."

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Flank me, boys: elsewhere at the after-party, Kirstin Davis channels the coyness of her character Charlotte as she's encircled by firm-chested hunks

Then at the premiere in Leicester Square on Monday, Miss Cattrall refused to sit through the film with her female co-stars and left to have dinner with Mario Cantone, who plays wedding planner Anthony.

Her deviation from the evening's schedule did not please the film's publicists.

Clearly wanting to dispel rumours of a rift, a spokesman initially said all four women had watched the film.

Told by the Daily Mail, however, that there were pictures of Miss Cattrall leaving a restaurant the spokesman could be heard cursing under her breath: "They've got pictures of Kim going out for dinner. What are we going to do?."

Last night publicist Ruth Dallatt acknowledged that Miss Cattrall did leave the cinema, adding: "The reason that Kim and Mario did not watch the film is that they promised their families that they would watch it for the first time together at the premiere in New York."

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Gimme shelter, Mario: carrying the heels that are obviously the shoes from hell, cheeky Kim hobbles behind behind co-star Mario Cantone

Duck for cover: Kim makes a barefooted getaway - without the girls - outside the afterparty

Miss Cattrall's dispute with Miss Parker apparently began over their paycheques for the film.

But she is not the only one to have a problem with the leading lady.

Leaving the premiere, Cynthia Nixon could be heard commenting on Miss Parker's flamboyant Philip Treacy hat

"What was SJP wearing on her head?," she was heard to say.

"What was going on there?"

A source said: "There's not a lot of love lost between them either."

Together for the cameras: it was all smiles for the fans at the premiere but it seems tensions were bubbling below the surface between the on-screen best friends