A son who strangled his dad to death in a drunken brawl has been sentenced to two-and-a-half years in prison, after an Old Bailey judge agreed the killing was a "terrible accident".

Mark Patrick O'Connell, 24, from King Charles Road, Surbiton, strangled Patrick O'Connell, 51, to death at his father's flat in St George's Road, Kingston, on the May bank holiday last year.

He pleaded guilty to manslaughter last month, claiming he had been trying to restrain his dad after they quarrelled at the end of an all-day drinking binge. The two had shared a close and loving relationship, and "idolised" each other, said lawyers.

Judge David Paget, sentencing Mr O'Connell at the Old Bailey on Monday, said: "I accept that these are wholly exceptional circumstances.

"No one can be in any doubt that you are overwhelmed by remorse at having killed your father. Whatever this court does to you, I am in no doubt that part of your punishment is that you have to live with the knowledge that you took his life - not intentionally, but because you had had too much to drink."

Pathologists' reports showed the strangulation had been for less than 20 seconds, and Mr O'Connell had died from a heart attack caused by the trauma rather than from asphyxia.

On the day of the killing, father and son had been drinking all afternoon at pubs, including the Castle in King Charles Road and the Duke of Buckingham in Villiers Road. They were joined during the day by two of the young man's cousins, and they passed the day in high spirits.

Mark O'Connell admitted to drinking between nine and 15 pints before he and his father left at 8.15pm to return to Patrick O'Connell's flat, in order to comply with a curfew the older man was under as part of bail conditions for a knife assault charge.

They were so drunk they could not open the door and had to be let in by Patrick's girlfriend, Susan Tuck.

Prosecution barrister Brian O'Neill told the court: "She described them as happy drunk', laughing and hugging. But the mood of joviality didn't last long.

"For some reason no one has been able to explain why an argument broke out."

The pair struggled on the floor, and Mark O'Connell decided to leave. He went into the communal hallway and kicked and broke several windows.

His dad followed him, calmed him down and persuaded him to come back inside. They came back hugging, but were soon fighting once more, resulting in the younger man straddling his dad and holding him down by the neck. Ms Tuck dragged him off, but discovered Mr O'Connell was not breathing and his eyes were wide and staring.

Panicking, the pair called the emergency services but Mr O'Connell was pronounced dead at 11.02pm.

A distressed Mark O'Connell told police at the scene: "He wouldn't stop, he was always on at me. I held him down to stop him, he can cause some real damage."

Judge Paget gave Mr O'Connell credit for his guilty plea of manslaughter, but said he could only reduce the sentence to two-and-a-half years because of the severity of the crime.

As a tearful Mr O'Connell was taken down to the cells, he mouthed to his family in the public gallery above "love you" and loud sobbing was heard.

Mr O'Connell's mum Stephanie Heather and some family members supported him throughout, but others, including many of Patrick O'Connell's fourteen brothers and sisters, wanted him tried for murder.

One said: "It's early days for that. But time's a great healer."