Operatic boy band Collabro have been crowned the winners of Britain's Got Talent.

The five-piece musical theatre act impressed the judges and the voting public with their performance of Stars from the musical Les Miserables.

Opera singer Lucy Kay, who lives in Glasgow, was runner-up, while teenage rap duo Bars and Melody, the bookies' favourites, finished third.

Collabro pick up £250,000 and a slot performing at the Royal Variety Performance for winning the ITV series.

The band - which includes 20-year-olds Richard Hadfield and Matt Pagan, Michael Auger and Thomas Redgrave, both 24, and Jamie Lambert, 23 - formed only a month before their first audition for the show.

After presenters Ant and Dec announced the result, Lambert said: "For everyone who voted, you're absolutely amazing. Judges - thank you so much. And to Lucy as well, she's absolutely incredible."

"Thank you Collaborators, we love you!" Hadfield added.

Collabro's rousing performance achieved a standing ovation from all four judges.

Simon Cowell said: "You know what I like about you guys is that you have steel in your eyes when you sing. You are totally focused, you know exactly the kind of group you want to be.

"The first time I heard that song it was fantastic. This was even better. This was a step up. This was a performance where I could tell you wanted to stamp on this competition and win the competition, and I like people who want to be winners."

Comedian David Walliams said: "It was wonderful. You couldn't fault it. It was perfection. I see really, really big things for you guys."

Alesha Dixon added: "I could feel that passion from you. I loved it."

Actress Amanda Holden said: "It was another faultless performance."

After the result, Lucy Kay said: "To the guy who bet £1,000 on me winning, I'm so sorry."

The 25-year-old was praised by the judges for her brave choice to sing Nessun Dorma, which is typically performed by male singers.

Cowell said: "When we first saw you, you were a shivering wreck. I remember that first audition. Then you come out tonight and choose arguably the world's hardest song to sing, even if you're a guy.

"For a girl it was so gutsy, it was so beautiful. You literally shone like a diamond tonight.

"Any other year, that is a show-winning performance."

Walliams said: "I was completely blown away by that. You sang it with such intensity and passion."

Third-placed Bars and Melody performed a self-penned anti-bullying song which has gained more than 30 million views on YouTube from their first audition.

Thirteen-year-old Leondre Devries and his friend Charlie Lenehan, 15, who wrote the track, were praised by Cowell, who said: "You are the nicest, sweetest kids I have ever met. I hope my little Eric turns out like you."

It was disappointing night for salsa dancing duo Paddy and Nico who finished ninth after an energtic routine to a modern version of the Tito Rodriguez classic Mama Guela.

Sarah "Paddy" Jones, 79, and her Spanish partner Nicolas Espinosa had been forced to withdraw from the live semi-final after she injured her ribs during rehearsals but made a last-minute recovery.

The pensioner, who has already won a talent show with Nico in Spain, managed to raise Cowell's eyebrows during her performance with some racy moves.

Cowell said: "Paddy, you are a little minx aren't you?

"I love the two of you but Paddy in particularly. You are a true inspiration. You are a fighter and you came back from injury to make a point tonight in the finals of Britain's Got Talent.

"I know how much this would mean to you in front of the Royal Family."

Holden said: "We've celebrated the 70th anniversary of the D-Day landings this week, and the tenacity and heroism of the older generation in Great Britain is phenomenal. What you achieved on stage is second to none."

Other finalists included dance troupe Addict Initiative, impressionist Jon Clegg, high-heeled dance trio Yanis Marshall, Arnaud and Mehdi, singing guitarist James Smith, swing group Jack Pack and illusionist Darcy Oakewere.