Indie quartet Alt-J have won the Barclaycard Mercury Prize for their debut album An Awesome Wave and promised to celebrate in very un-rock 'n' roll style - by taking their parents out for dinner.

The group, who met at Leeds University in 2007, looked stunned as they collected the award - despite being the bookies' favourites as the ceremony got under way.

They picked up the £20,000 prize at the event at the Roundhouse, in Camden, north London, which was hosted by Lauren Laverne and screened in a brief five-minute slot on Channel 4.

Accepting the award on stage, the band - Thom Green (drums), Joe Newman (guitar/vocals), Gwil Sainsbury (guitarist/bassist) and Gus Unger-Hamilton (keyboards) - said there were too many people to thank. They said: "We might just thank everyone on team Alt-J who has ever made a difference." They also thanked their parents for "not making us get jobs".

Speaking backstage, Unger-Hamilton said the £20,000 prize money would not change their lives too much. He said: "It won't nearly pay off our student loans." But he admitted to being a fan of his own work, saying: "I like listening to it and I think that is a testament to it, it's the same four guys."

Newman said the band would take their parents out for dinner but would also celebrate in more traditional rock star style by going out for a drink.

Newman also revealed his father had tried to cash in on the band's success but failed. He said: "My dad went to the bookies when the album was being made in January to try and put a bet on the Mercury Prize, but they didn't know what he was talking about".

HMV's Gennaro Castaldo said the win would see the band, who have previously hardly troubled the top 40, enjoy a "five or six-fold" increase in sales.

He said: "Alt-J are one of a handful of nominated artists along with Django Django and Ben Howard who are reaching a tipping point in their careers. Winning the Mercury Prize, and the recognition and huge exposure it brings, is just the catalyst they need to connect with a much wider audience and step up to the next level, like Elbow did a few years back."

They beat acts including rapper Plan B to win the award and singer-songwriter Richard Hawley, who missed out again - six years after losing to Arctic Monkeys. Simon Frith, chair of the judges, said Alt-J's music had a "hypnotic" quality and was a deserved winner. He added: "One of the things the Mercury has always been about is sounding fresh."

The Press Association, photo by itswhatiminto.com