A teenage thug who launched a vicious attack with a broken bottle after gatecrashing a party has been locked up for over six years.

It was the third offence Billy Lee had committed using a bottle as a weapon, Maidstone Crown Court was told.

The 18-year-old was already serving two years youth custody imposed in February over a violent clash between rival gangs at Sittingbourne railway station when he appeared for sentence for the latest offences.

It happened at a party at a house in Cooks Lane, Sittingbourne, on November 7 last year.

Wounding victim Steven Mandinyena was returning to the house with drinks at about 8pm when Lee and other “drunken gatecrashers” arrived.

They refused to leave and Lee then struck the victim with the bottle causing deep cuts about 10cm long to his upper and lower arm.

The attack was witnessed by Mr Mandinyena's girlfriend Kimberley Arnold.

Judge Charles Macdonald QC said Lee then turned his attention to Carol Hughes, who arranged the party for her daughter, as she tried to stem the bleeding from Mr Mandinyena’s arm.

Lee attacked her with the bottle cutting her left arm. She needed hospital treatment but was not seriously injured.

Mr Mandinyena was taken to Medway Hospital and then needed specialist treatment at the Queen Victoria Hospital in East Grinstead as the glass penetrated layers of skin into the tissue.

He has been left with some disability and scarring.

Lee, of Quinton Road, admitted wounding Mr Mandinyena with intent to cause grievous bodily harm.

He denied assaulting Ms Hughes causing actual bodily harm, claiming mistaken identity, but was convicted by a jury.

The judge said he could have concluded Lee met the statutory definition of a dangerous offender but did not make that finding because he was young and there was the “possibility of change”.

He accepted the teenager had a deprived background which he described in an eloquent letter to the court.

“Nevertheless, custody is inevitable,” he added.

Lee was sentenced to five-and-a-half years for wounding and nine months consecutive for the assault offence, making a total of six years and three months in a young offenders institute.

Robert De Banzie, defending read out Lee’s letter to the court in which he declared: “I am truly sorry for my disgusting behaviour in the past."

He added time in custody had given his client some insight into the difficulties that had landed him before the court again.

“He now sees some light at the end of the tunnel for the first time,” he said.