A man "fuelled by jealousy and rage" scarred a total stranger with a kitchen knife for dating his ex-partner, a court has heard.

Derek Malcolm, 34, let himself into his former partner’s home in Prestwich in the early hours of August 7 last year as the pair were sleeping and viciously punched the man as he lay in bed.

He then went downstairs and returned with a kitchen knife which he used to viciously attack the man, who was a total stranger to him, Manchester Crown Court heard.

Alaric Bassano, prosecuting, said: “He went into the bedroom and, fuelled by jealousy and rage attacked the man next to her on the bed.”

Mr Bassano told the court how Malcolm, of Langley Grove, Prestwich, had previously been in a relationship with the woman.

Bury Times: The case was heard at Manchester Crown Court, Crown SquareThe case was heard at Manchester Crown Court, Crown Square (Image: Newsquest)

When attacking the man, Malcolm barged his ex-partner out of the way and into a piano as she tried to pull him away.

Malcolm then slashed the man in the head with a knife, leaving him with permanent scarring.

The next day he then sent threatening messages to his ex-partner to try and stop her from cooperating with the police.

Mr Bassano said: “He labelled her a grass, a rat and made veiled threats.”

A statement from the man, a HGV driver and ex-soldier that Malcolm had attacked, read out by Mr Bassano spoke of the profound impact the incident had had on him.

He said: “I was in the armed forces for nine years and I have never been scared of anything, but this happening to me has had a really bad effect on me.

“I can’t relax because of the uncertainty and just how unexpected this was. I have lost a lot of confidence in going to places on my own and I do not trust anyone.

“I have never been kept awake at night, regardless of what I have been through, but after this happened I have been completely unable to relax and rest.”

He added: “I can’t relax because I feel that I can’t keep myself or my parents safe whilst this man is free to walk the streets.

“I have seen some horrendous things throughout my life and certainly my time in the army, including the loss of friends and those friends losing their lives in front of me.

“I have never been scared, and things have never affected me in the way that this has.”

Malcolm was arrested soon after and was convicted of wounding with intent, assault by beating and perverting the course of justice after a trial which finished on November 11 this year.

Adam Roxborough, defending, argued that the assault was not "sustained" but rather the wounding had been caused by a single blow, while there also had not been any "significant" planning involved.

He said: “It was a confluence of events, on this particular night, which led to this offending.”

ALSO READ: Potholes and knife crime among biggest concerns for Bury residents

ALSO READ: Police minister responds after Bury knife crime problems

Mr Roxborough told the court that Malcolm "has a meritorious side to him" and that he "hopes he can return to being that person again".

Judge Hilary Manley told the court that Malcolm had shown "no real remorse" and no insight into his "distorted thinking" during the course of his trial.

She did not accept that his violent actions were "an isolated incident" and reminded the court of the profound and lasting impact he had had on his victims.

Judge Manley sentenced Malcolm to a total of 18 years in prison.