Stephen Mayor, 19, is beginning 14 months in youth custody after he admitted inflicting grievous bodily harm on 43-year-old Robert Weedon.

He suffered a fractured skull and was in intensive care for six weeks after being felled on the Flat Iron car park. He now has speech difficulties and needs constant supervision.

However the Guardian can reveal that on the evening in question Mr Weedon and his partner Helen Gillies had been enjoying a night out with Mayor's parents David and Julie.

They had been drinking in The Sir Henry Tate pub but trouble erupted as the group left. A disagreement broke out and Stephen, who'd joined his parents, threw one punch which turned the lives of both families upside down.

Speaking for the first time about what happened Mayor's mum Julie, 38, of Burgh Meadows, Chorley, said: "Stephen never meant for what happened - it was a chance in a million that all this could result from one punch. He is a great son - he is very dedicated to his family and his girlfriend, who is absolutely distraught."

Mr Weedon's partner Helen, of Shakespeare Terrace, Chorley, said it was a tragedy for everybody: "I've known the family for 25 years. I've seen Stephen grow up. I feel sorry for his parents because they are losing their son for quite a long time but my daughter Hannah hasn't got a father anymore. I've been with him for 18 years and you think about it every day."

For more on this story, see this week's Chorley Guardian.