A one-legged man who stabbed his mother's drunk and violent boyfriend to death has been jailed for four-and-a-half years.

Dean Huggett, 21, walked into his living room in Dower Walk, Crawley, to find Peter Finch attacking his mother, Jackie Jones, last August.

He wrestled him to the floor but Mr Finch, 39, overpowered Huggett and began strangling him.

At that point, Huggett reached for a knife that had been used to fix a CD player in the living room and plunged it into Mr Finch's back.

Huggett denied murder but admitted a lesser charge of manslaughter on the grounds he was provoked.

The court heard Mrs Jones persistently lied to police about the incident, framing another man for the stabbing while Huggett went on the run.

He was arrested a few days later in Brighton and admitted stabbing Mr Finch.

Defence barrister James Scobie told the court Huggett had been subjected to a "squalid" upbringing.

Both his parents were chronic alcoholics and he was the victim of physical abuse by both of them.

He had often witnessed violence and once saw his mother stabbed.

Huggett's misfortune was compounded when he had his left leg amputated after an accident at a railway station in 2002.

The pattern of violence and alcohol abuse continued when his mother moved in with Mr Finch last spring, the court heard.

Judge Anthony Scott-Gall said Huggett had grown up in a "dismal and bleak" environment of "degeneracy and violence".

He said Mr Finch had a long history of alcoholism and violence and just before the stabbing had subjected Mrs Jones to a brutal attack.

On the day, they had both been drinking heavily and Mr Finch had consumed more than four times the legal drink-drive limit.

Judge Scott-Gall said: "It is not an environment for anyone to grow up in."

The judge told Huggett: "When in drink unfortunately the deceased was capable of significant acts of violence.

"You were in a hopeless situation. Your mother was being physically abused."

Huggett was asleep in his room after smoking cannabis but was awoken by a row between his mother and Mr Finch.

The judge said: "I accept it was never your intention to kill.

"I am not persuaded you are a high risk to society. You are significantly disabled for a young man."

He gave Huggett credit for his guilty plea and his remorse. Huggett showed no emotion as he was sentenced.

Mr Scobie said: "My client regrets enormously what occurred that day. There is genuine remorse."