Read the full transcript of the Joey Barton interview | All the times Barton has said "sorry" before

Joey Barton has been accused of many things - and been found guilty of some - but dishonesty is one charge that would never stick. In a selflacerating deconstruction of his frailties and failures - “I am indefensible,” he admitted - the most contentious English footballer of his generation has spoken openly of his recent incarceration and his troubled relationship with alcohol.

The Newcastle United midfield player was released from prison in Manchester three months ago after serving 74 days of a six-month sentence for assault and affray, his spell behind bars related to a drink-fuelled incident in Liverpool city centre. He was subsequently given a separate four-month suspended sentence for causing actual bodily harm on Ousmane Dabo, his former Manchester City team-mate.

There have been other disgraces and indiscretions - a lit cigar in the eye here, a skirmish with a teenage Evertonian there - and as he makes yet another attempt at redemption, Barton, who is now teetotal, is neither seeking sympathy nor claiming innocence. “My reputation will always precede me until the day I die,” he said. “For some people that probably can't come quickly enough.”

On Tuesday, Barton played for Newcastle's reserve team against Middlesbrough, his first game since completing a six-match suspension for his training-ground altercation with Dabo. The location was Billingham Synthonia, the only known club named after an agricultural fertiliser (synthetic ammonia), and afterwards he spoke outside Synners Bar. Punchlines should not be necessary.

The 26-year-old understands that his behaviour has invited derision and loathing, that some believe Newcastle, who spent £5.8million to buy him from City in July last year, should have sacked him. “They have an argument,” he said. If he features in Saturday's derby fixture away to Sunderland - an early challenge to his temperament - voices will be raised against him.

“I am very, very fortunate,” Barton said. “And now I have to make the most of it. There are people that have been in jail longer than me. I was watching the boxing the other night and saw Bernard Hopkins. He had been in jail for four years and managed to turn his life around. I just have to try to take inspiration from that. I have messed up on more than one occasion, but nothing sobers you up like the reality of going to prison. I know it's the last chance saloon.”

The intention is there, but it has been there before. Will it - can it - be different? “Time will be the great teller,” Barton said. “One thing I do know is that I'm sober. I haven't had a drink for ten months, since December 27. That's a start.

“It's well documented that I've had problems with alcohol and the thing I went to jail for was alcohol-related. I'm not using that as an excuse, because it was my own stupidity.”

In any case, it could only be a partial explanation. “Things will be levelled at me that I had a fight with Ousmane when I was sober,” Barton said. “I understand that.” But he pointed to a recent training-ground episode in rugby union and hinted at double standards.

“I've looked at the Danny Cipriani/Josh Lewsey incident and while I don't know exactly what went on there, what I do know is that for sportsmen in full-contact sports, tempers do get heated,” he said. “I have seen that throughout my career. Maybe if it was English guys, it never leaves the training ground. It does take two to tango. People must remember that. I'm disappointed at myself for the way I reacted, but there are lessons to be learnt and if I don't learn those lessons, my career will be over.”

Barton expressed gratitude for the unwavering loyalty of Kevin Keegan, the former Newcastle manager, and his primary objective is to “give it his all” for his club. “The last 18 months have been hell,” he said. “I've been living with a court case over me. If I am brutally honest, I knew that I was going to jail.

“I'm not asking for anyone to feel sorry for me, by any means. If anything, I deserve every bit of criticism that was levelled at me. I can't stand here and try to defend myself because I am indefensible.

“Prison wasn't a nice experience and hopefully people can see the stupid mistakes I've made and maybe they won't make as many. Now I can be a shining beacon for kids who have been in trouble like me.”

That suggestion will prompt cynicism, yet away from the spotlight, Barton is continuing to receive treatment from the Sporting Chance Clinic and recently donated £25,000 to the Tamsin Gulvin Fund, a charity established to support people who have addiction problems and no financial backing. He is serving 200 hours of mandatory community service, but plans to do more.

“I have probably made a lot more people unhappy than a normal person will, but maybe young kids look at the likes of Michael Owen and David Beckham - who are unbelievable professionals, who are squeaky clean - and can't relate to them,” he said.

“I've met people on the street and I have met people in prison and they relate to you. Hopefully I will be able to reach those people who have been unreachable.”