In an interview with Newstalk ZB, Sir Peter said that looking back on his career, he hoped he had been compassionate and looked after the underdog.
"I believe that every person in a democracy is entitled to his or her self-esteem and is entitled to be cared for in a reasonable fashion so that really has been one of my prime considerations and that's why I've been one of the movers for penal reform -- so that people can express their individuality and have some sort of life, even if they're in prison."
Since being admitted to the bar in 1960, Sir Peter has campaigned tirelessly for prisoner rights, advocating for decent conditions during incarceration, rehabilitation and addressing the causes of crime.
Presiding over the Howard League for Penal Reform for 30 years, he resigned in 2011 to establish the Prison Reform Society.
He has argued for less focus on imprisonment and more on alternative residential facilities where offenders can do programmes aimed at changing their behaviour.
Sir Peter said he accepted the award on behalf of penal reformers who had worked to improve conditions for the past 100 years.
"People that have worked to improve conditions, who've improved human rights, people who've received no money, no consideration, a lot of them women going right back to the beginning of the century."
He has taken on clients in some of our most significant trials, including Arthur Allan Thomas, Terry "Mr Asia" Clark, and in the Bassett Rd machine-gun murders case.
Sir Peter, who is continuing his eight-year battle with prostate cancer, said he felt it was his duty to represent those who wanted his services.
"But I must say I probably went beyond that at times, Arthur Allan Thomas would have been an example of that.
"I think that when you're absolutely immersed in a case you wake up at 3am and you think of things -- there's no doubt, it's very, very difficult to dissociate yourself at the end of the day. There's no doubt that it takes over your life ... the law is a very, very demanding profession."