A judge threw out an appeal brought on behalf of a teenager who stamped on his drunk friend’s head.

Lawyers acting for Matthew Stevens, 18, claimed the eight month sentence he was given by Swindon Youth Court in September for two counts of causing actual bodily harm and a single charge of assaulting an off-duty special constable was excessive.

Dismissing the appeal against sentence at Swindon Crown Court on Monday morning, Judge Jason Taylor QC said: “We are firmly of the view when we look at this sentence in the round, eight months was not manifestly excessive. It wasn’t even excessive.” He suggested the sentence could be considered merciful.

Stevens was sentenced in September, just four days before his 18th birthday. A month earlier he was found guilty of two charges of ABH and later pleaded guilty to assaulting a special constable and criminal damage.

George Threlfall, for the Crown, told the court on Monday morning that Stevens, his victim and a man who has never been identified had visited a friend in Redhouse on June 28 last year.

The victim had brought a case of beer, which they were drinking. The boy was sick in the house, splashing Stevens – then 16-years-old - with vomit.

Stevens, his victim and the mystery man were thrown out of the house. The boy in whose room they had been drinking heard shouting and went outside to find the third man kick the victim three times then stamp on his head.

The victim was walked to nearby Dussek Place, where Stevens was seen to punch him twice while the unidentified man struck him again. They were spotted by a woman, who recognised Stevens, and later caught up with the men.

Stevens was seen punching the victim in the face, causing him to fall to the ground. He then kicked him in the head, knocking him out. He tried to pull the victim up, telling bystanders he did not want to go back to prison. The mystery man and Stevens ran away.

While awaiting his trial, the boy was caught by an off-duty special constable damaging the Tesco building where he worked. The officer showed his warrant card but was assaulted by the teen.

The magistrates gave him eight months detention and training order for the ABH charges and a concurrent sentence for assaulting an emergency worker.

Leanne Ballato, for Stevens, argued that the sentence was manifestly excessive. The magistrates had failed to properly apply guidelines on sentencing youths that directed courts to reduce the adult sentence by half to two-thirds when sentencing children aged 15 to 17.

She acknowledged that her client had an appalling record for one so young, with convictions for robbery and attempted robbery on his list of 30 offences.

However, Ms Bollato said her client had significant mitigation. He had had a difficult upbringing and had struggled with addiction to alcohol and drugs like Xanax. However, a new girlfriend and her mother had helped shift him onto a different path. Until he was sent to custody in September he was enrolled on a college course and working part-time at Tesco. There had been considerable delay in the case coming to trial.

She asked the court to consider imposing a youth rehabilitation order, which would allow him to do work with the probation service.

Stevens, formerly of Millgrove Street, Redhouse, appeared in court over the video link from Parc young offenders’ institute.

Judge Taylor gave three reasons for dismissing the appeal. First, the two-thirds discount for 15-17-year-olds was not “set in stone”. Second, the guidelines applied to people of previous good character and Stevens’ record was “absolutely appalling”. Finally, the conviction for assaulting an emergency worker should have attracted a consecutive sentence – but the magistrates in September had had an eye to the total sentence Stevens received.

The judge, sitting with two magistrates, said it was the bench’s sincere hope Stevens continued the good progress he had made before being sent into custody.