A troubled son who was jailed for stabbing his bullying dad to death deserves every day of his 18-year prison sentence, judges today ruled.

Patrick Luke Murphy, 31, killed 54-year-old Joseph Murphy at their home in Hectorage Road, Tonbridge, in May of last year.

It was the culmination of years of abuse, his lawyers claimed, and occurred after Murphy had gone to a supermarket to buy knives.

He was found guilty of manslaughter and the wounding of his brother, Mark, and jailed for 18 years at Maidstone Crown Court in March.

Today, he appealed against the sentence, but saw his case rejected by three senior judges at the Court of Appeal in London.

Lord Justice Beatson said: "Although it may be that this sentence is towards the top of the range, it is nowhere near being manifestly excessive."

The court heard Mr Murphy Snr was killed in a brutal stabbing attack, in which he sustained injuries to his chest and arms.

The son claimed the attack had happened after he walked out of the home following an argument about a phone charger.

He sold his phone and used the cash to buy strong lager which he drank in a park, before going to buy knives.

CCTV footage showed him wrapping up the blades outside a supermarket shortly before the assault.

Following the attack on his dad, Murphy's brother, Mark, tried to intervene and suffered an arm injury in a struggle with Patrick.

Murphy claimed self-defence and, although he was acquitted of murder, was found guilty of manslaughter of his dad and wounding his brother.

Today, his barrister James Turner QC argued that the "dysfunctional" background of the family mitigated the seriousness of the crimes.

Murphy had been subjected to bullying abuse from his father over the years and police had been involved many times in domestic incidents, the court was told.

It was also wrong to say that Murphy's brother was a "vulnerable" victim just because he has epilepsy.

Rejecting the appeal, Lord Justice Beatson, sitting today with Mr Justice Haddon-Cave and Judge Geoffrey Marson QC, said the sentence was justified.

"Fuelled by drink and after an argument, he went out and purchased knives, which he brought to the scene with the intention of confronting his father," he said.

"After he had committed the attack, he stated 'I should have done that years ago'."

The 18-year term was upheld.