A jealous man who beat his love rival with a metal bike chain and bit his arm when he caught him in bed with his girlfriend has been jailed.

Barry Robertson lashed out with the weapon after smashing his way into the Dover home of Lee Shearer.

Despite the trio only knowing each other for three weeks, Robertson saw Mr Shearer as his "new best friend", Canterbury Crown Court was told.

But "sexual jealousy" on finding his lover with him in the early hours of June 5 triggered his violent outburst.

Having smashed the window and front door, he attacked Mr Shearer to his head and body, leaving him with multiple cuts and bruises, and also threatened to kill him.

The 43-year-old then struck a police officer with the Raleigh-branded chain, clipping his cheek, before he was eventually arrested.

Now, for what was described by his own barrister as a "crime of passion", Robertson has been locked up for seven years.

Passing sentence on Wednesday, Recorder Amy Nicholson told him he had "hunted down" the pair, intending to inflict serious injury in a "ferocious" attack.

Robertson, of Douglas Road, Dover, pleaded guilty to aggravated burglary, possessing an offensive weapon, criminal damage, assault causing actual bodily harm, threatening to kill and assault on an emergency worker.

The court heard he, his girlfriend - referred to in court as Kat McKenzie - and Mr Shearer had spent the day socialising before heading back to Robertson's home for food.

Prosecutor Peter Walsh said Robertson continued drinking and became abusive and aggressive towards Ms McKenzie, calling her names and grabbing her.

As the abuse escalated, Mr Shearer stepped in by trying to calm him down and saying he would take her back to his flat.

"The defendant seemed to accept that and went to bed," added Mr Walsh.

He told the court that once at Mr Shearer's home in Edred Road, he and Ms McKenzie were "intimate for the one and only time" before going to bed.

But at about 3am Mr Shearer heard the window being smashed and Robertson screaming.

“When he peeled the curtains open he saw the defendant with a metal chain in his hand," Mr Walsh told the court.

"In order to protect Ms McKenzie, Mr Shearer told her to go into the bathroom for her own safety and lock herself in.

"But as the defendant smashed his way through the bedroom window, he immediately started attacking Mr Shearer numerous times to the head and body with the chain, telling him he was going to kill him."

Mr Shearer was eventually able to force Robertson out of the flat and he called police.

Officers arrived about five minutes later and were speaking to the victims when Robertson "reappeared at the bedroom window, lunging at his partner", said the prosecutor.

But as a constable grabbed him by the scruff of his coat, he swung the chain, clipping the officer's left cheek and eye area.

"He had to step backwards to avoid more serious injury," continued Mr Walsh. "The officer said the defendant's intention was clear, looking straight at him before actioning his chain towards him."

“In my judgment it is clear these offences were born out of sexual jealousy...”

A Taser had to be produced by another officer before Robertson became compliant and dropped the blood-stained weapon.

The court was told he later claimed he did not know they were police, despite being in uniform and having arrived in marked vehicles with flashing blue lights.

Mr Shearer suffered 14 separate injuries to his head, face, arms, shoulder, chest and back.

Dudley Beal, defending, told the court that the chain, although "fairly heavy-duty", was one for securing a bike and had not been "specifically adapted" to use as a weapon.

He added that Robertson's threat was that he "should kill you" rather than one of "I'm going to kill you", and that it was uttered "in the heat of the moment".

"This was a crime that occurred out of passion. He had known Lee Shearer for three weeks and he found his girlfriend in bed with his new best friend," said Mr Beal.

Jailing Robertson, Recorder Nicholson said a neighbour who alerted police reported hearing him say he was "going to commit murder".

"In my judgment it is clear these offences were born out of sexual jealousy. You did not like the bond formed between Ms McKenzie and Mr Shearer and under the influence of a significant amount of alcohol you became aggressive and abusive," she told him.

"When you woke to find they had gone, you formed the intent to hunt them down and attack them.

"The chain was taken to the scene with the intention of inflicting very serious harm and you did cause significant actual bodily harm.

"You smashed your way into someone's home at night and you were heard by a neighbour as they called police to say that you were going to commit murder, and as you attacked Mr Shearer with that chain you told him you were going to kill him.

"This was a terrifying ordeal for your victims. The trauma this attack caused was deeply evident in the bodyworn camera footage, which also revealed you bit Mr Shearer on the arm, leaving a clear mark."

The judge said the "ferocity" of his attack was demonstrated by the "blood-splattered walls" and the fact part of the bike chain "wrapping" came off.

Robertson was told he will have to serve at least two-thirds of his jail term before he can apply for parole.