As the government tries to tackle anti-social drinking by targeting parents, the BBC's Jon Kelly speaks to a couple who say they are powerless to prevent their son abusing alcohol. All names have been changed.
Luke's parents say cut-price alcohol sales are the problem
Luke Thomson had always been a model son - caring, sensible and hard-working.
But after falling in with a group of friends whose lives revolved around heavy drinking, his parents soon witnessed an ugly transformation.
As a result of his bingeing, Luke would become aggressive, abusive and suicidal. His work suffered, he spiralled into debt and lost his driving licence.
Horrified at the changes in their son, mother Amanda, 53, and father Andrew, 55, have battled to help him, but Luke - now 21 - remains beyond their reach.
"It's heartbreaking to watch this happening to a boy that I love," says Amanda.
"But however much we try to help him, it's his friends he listens to - not his parents. That's what the government don't understand."
Like Andrew, she is deeply sceptical of the home secretary's plans to prosecute adults whose children are caught boozing in public.
For three years they have tried everything to curb Luke's drink problem, to little effect. Stripping the house of alcohol has failed, as have attempts to keep him away from the friends whose influence they believe has had such a pernicious effect.
And as a professional couple from the rural south of England, Andrew and Amanda warn that their situation could happen to anyone.
Luke had been a well-behaved and considerate teenager, but his downward spiral began on his 18th birthday when the new group of friends thought it would be funny to get him hopelessly drunk.
After staying up with his son all night as the teenager experienced his first dose of alcohol poisoning, Andrew hoped it would at least put his son off booze for life. But he was to be proved wrong.
"We'd never had any problems with him growing up, and I'd always been quite anti-alcohol," Andrew recalls.
"But from being a sensitive young man, he turned into someone with a split personality."
As they grew more and more concerned about Luke's increasingly heavy alcohol intake, his parents found they were powerless to help.
He moved into a flat with his new friends, who were used to spending the entirety of each morning sleeping off their hangovers.
Andrew and Amanda believed the group were taking advantage of their son, who had saved carefully as a teenager to buy his own car.
But every time his parents tried to reach out to him, Luke pushed them further away.
"I'd tell him his drinking was out of control, and he'd say, 'I'm too old for you to tell me what to do,'" remembers Amanda.
"Eventually I was so concerned that I spoke to one of the girls he lived with that I thought Luke was becoming an alcoholic.
"So she went and said to him that all I wanted to do was interfere and he should keep away."
Luke's drinking came to a head when, after a drunken row with his friends, he sat alone at the wheel of his car.
He had kept the engine switched off, but when the police spotted him he was charged and eventually given a 20-month ban.
Unable to drive, his prospects at work as an estate agent suffered and his confidence plummeted further.
Two months later, addled with debt, he moved back home. But Andrew and Amanda were still unable to stop his binges.
His mother believes that a girlfriend might help Luke find the self-assurance and maturity he needs to break out of his self-destructive lifestyle, but a vicious cycle keeps him trapped.
"Because he's always drunk he finds it difficult to meet girls. And that makes things worse, because it means his confidence is hit even harder," she says.
"Until he admits he has a problem and gets help, there's no way out for him."
Andrew says his family's experience shows that parents cannot always control the anti-social drinking of children - grown-up or under age.
"The real problem is how cheaply alcohol is sold in shops and supermarkets, and how it is portrayed in the media - soap opera characters turning to it at the slightest problem.
"Punishing parents is not the solution. We are already the ones who suffer the most."