The Sport and Recreation Alliance's parliamentary liaison officer Simon Butler talks sports politics: At the Excel Centre in east London Team GB's boxers have begun their quest for Olympic glory. Among the medal hopefuls are Tom Stalker, who won gold at the 2010 Commonwealth Games, and Natasha Jonas, the first female boxer ever to qualify for the British Olympic team.

Natasha and Tom will be familiar to you if you caught ‘Knockout Scousers’ on Channel 4 last month, which follows three boxers from Liverpool on their tough journey to Olympic qualification.

The documentary presents the challenge of making the final squad from an athlete's perspective, and is a useful reminder of what an accomplishment it is just to compete at the Games, let alone come away with a medal. But what comes through even more strongly from the hour-long film is that boxing has the power to turn lives around.

Tom Stalker won gold in Delhi two years ago, and goes into London 2012 as the world's number one light welterweight. But it is easy to see how things could have turned out very differently for him: he describes how drugs, alcohol and partying dominated his late teenage years, and how he lacked direction after leaving school at 16.

The gym that Tom started training in, which has since closed down, made the difference by providing a much-needed outlet for aggression: "Once we got the gym the crime rate went down," he says, "because all the bad lads were in the gym."

Interestingly, according to his mum he didn't have a natural talent for boxing. Instead, he worked at it in the gym every day until he could hold his own in the ring. "That fight meant the world to me" he says while watching grainy footage of his first amateur bout.

Another 'knockout scouser' is James 'Jazza' Dickens, who won't feature at London 2012 having opted to turn professional. Like Tom, it was a humble boxing gym that made the crucial intervention – so humble that the roof still has a huge hole in it and plaster is falling off the walls.

"My gym's a gym for human beings" says the owner. It's a far cry from the state-of-the-art facilities in Sheffield where top British athletes train, but that doesn't undermine the importance of the gym for young kids in Liverpool.

"Where Jazza's from there are a lot of drugs, a lot of grief and a lot of disruption…boxing has saved him." A coach from another of the city's boxing clubs agrees: "We're keeping these kids off the streets."

Aside from their home city, the one thing that unites all three knockout scousers is their love for the sport and commitment to being the best. Asked how his daily 4am runs would help his chances against opponents in the ring, Jazza Dickens replied: "I'm going to be the one who wanted it more because I was up earlier than them."

The producers of the documentary deserve much credit for drawing attention to the valuable contribution made by boxing clubs within disadvantaged communities.

This is a powerful political message, which resonates even more as we approach the anniversary of the riots which spread across London, Birmingham and several other regions last summer.

The significance of the anniversary and its cross-over with the Olympics was the subject of discussion at a recent event hosted by the All Party Parliamentary Group for Boxing, and a full write-up (including video clips) can be found on their blog.

To continue this theme, the group will be embarking upon an inquiry in September to explore in more detail why boxing is a valuable tool for communities, and what the government must do to harness it.

Meanwhile if you haven’t yet seen Knockout Scousers, it’s available on 4OD for another two weeks, and I can’t recommend it strongly enough.