A thug who floored a friend with a single punch during a drunken argument in a busy High Street has been jailed for three years.

Noel Langton, who has previous convictions for violence, lashed out and walked away with his girlfriend as victim Russell Whiteman lay unconscious on ground.

Mr Whiteman, who has metal plates in his skull from a previous injury, suffered a fractured eye socket and a serious cut to his head.

Father-to-be Langton, 39, later claimed he was not present at the time of the attack and said his partner Natalie Brown would confirm his alibi.

But after being told she was not supporting his account, he put his head in his hands and confessed: “It was me.”

The assault in Chatham High Street happened on the afternoon of February 12 this year while the three were drinking.

Prosecutor Martin Yale said Mr Whiteman was punched after he intervened in an argument between Langton and Miss Brown.

“He was knocked unconscious,” Mr Yale told Maidstone Crown Court on Tuesday. “He lost a significant amount of blood. When an ambulance attended he was still unresponsive on the ground.”

He was taken to Medway Hospital for treatment. He bled heavily from his nose.

Langton, who in 2004 was jailed for four and a half years for causing grievous bodily harm with intent, eventually said: "I am sorry. I didn’t want to hurt him. It was a go away moment. He kept saying he was a boxer. I am gutted.”

Mr Whiteman said in a victim statement he feared he would be killed. He added that Langton was unpredictable and said he would have to leave the area if the former friend “got out”.

He had metal plates on the right side of the head and was struck on the left side.

Langton, of Sturdee Avenue, Gillingham, admitted inflicting grievous bodily harm. He has 21 previous convictions for 31 offences.

Kerry Waitt, defending, said Langton was blighted by alcohol. A prison sentence meant he would not be present for the birth of his child in July.

Recorder Matthew McDonagh said it was fortunate the victim did not suffer even more serious injuries.

“I don’t doubt the ongoing effect on the victim is real,” he said. “It is urged you show genuine remorse. The view I form is it is really one of self-pity.”

Langton was sentenced to two-and-a-half years for grievous bodily harm and six months consecutive for breach of a suspended sentence for battery and threatening behaviour.