Vanessa Anne Hudgens plays geeky student Gabriella in the film

The TV movie about two pupils who fall in love while auditioning for a play, has been seen by 37 million people since it first aired in January.

Cherie Blair was among those who watched a special preview screening of the film on Sunday evening.

It will receive its UK TV premiere on the Disney Channel on 22 September. BBC One will show the film at Christmas.

High School Musical was something of a surprise hit, but Disney have been quick to capitalise on its success.

It has been shown 13 times on US television, and the soundtrack album has spent 23 weeks in the Billboard top five, selling 2.5 million copies.

Cherie Blair attended the screening in London's Leicester Square

It was also the first movie to be sold on Apple's iTunes store, and hundreds of schools have bought licenses to stage their own productions of the musical.

There will even be a Bollywood version of the movie, with the soundtrack re-recorded in Hindi.

The original was directed by Kenny Ortega, who was previously best known as the choreographer on Dirty Dancing and Ferris Bueller's Day Off.

When it was first shown, the film's teenage stars were also virtually unknown, but lead actors Zac Efron and Vanessa Anne Hudgens are now household names in the US.