"They couldn't believe they'd won," says Jo Mower, Liam's mum. "There was an incredible atmosphere, a big party with champagne everywhere." But it hasn't always been party time; like other families of talented young dancers, the Mower family has been very much involved in Liam's progress for the past five years. Jo Mower describes it as "massive teamwork".
From the first, she spotted something different about her third-born son (she has four) as "he loved music before he could walk" and would move his hands and feet to Michael Jackson and Whitney Houston. Once on his own feet, he was working out dance routines and "always loved an audience".
Liam (pictured left) isn't a show-off, though. Now 13 (14 in May) he is remarkably philosophical for someone who has had to cope with stardom so young: "It will be hard to leave Billy Elliot, but I suppose you've got to move on," he says. Picked from 3,000 hopefuls when he was 12 (he plays the youngest of the three Billys), he is getting taller and his contract runs out on June 3.
He began attending disco and rock 'n' roll classes in Hull when he was about eight. At 10 he was doing tap and modern dance with the Northern Theatre Company and a year later, while his brothers played rugby and football, he was doing ballet twice a week and travelling to class in Leeds every Saturday. There he received training under the Royal Ballet School's mid-associates scheme, which is the stage before joining the school full-time.
Already his parents were coping with unexpected travel and chaperone duties. His father is a pipe-fitter, and no one in the family had previously shown a talent for dance. Then came that extraordinary week last year when Liam secured his place at White Lodge, the school in London associated with the Royal Ballet, just after being chosen (after several auditions) for the plum role of the boy from a mining family who chooses ballet over boxing and makes it as a dancer. He has been on stage at the Victoria Palace Theatre two or three times a week for almost a year since then.
It has been exciting, but exhausting too and, for the moment, he is taking a break from White Lodge, returning to Archbishop Thurston school, his comprehensive in Hull, when he has his five days off each month. His mother says he had never spent a single night away from his family before he went to boarding school.
"The Royal Ballet School has been really supportive," says Jo Mower, "They even said he could get up later after nights he'd performed, but he felt he didn't want to be different. He was really happy there, so they are keeping his place open until September." Liam's academic work has to be kept up to date too and he has just done "really well" in his mock key stage 3 Sats, despite having to move back and forth to tutoring in London.
And the future? "Ballet is strongest, there's a voice - it may not be great but there is one - and I like acting. I want to do everything," says Liam.
He's certainly made a good start as the part requires singing and gymnastics as well as dance.
The search for young Billys goes on. Three boys share the role and have to stop when their voices break or they grow too tall. So, if you know a boy aged between 11 and 13, under 5ft 3in, with an unbroken voice and the potential to be a strong dancer, contact firstname.lastname@example.org.
Regional training is offered to likely candidates. Successful trainees will need a 'wow factor' to be chosen for the show, but many others can benefit from the experience of learning to sing, dance and act in a unique role