Prosecutors have decided there are no grounds to appeal 15-month custodial sentences given to the attackers of a 22-year-old man who was left in a coma.

Glen Dennis suffered head injuries when he was assaulted by four men in Coach Road, Saltaire, last June.

He was found unconscious on grassland with bleeding to the brain and was in a coma for three weeks.

He is now unable to live independently.

Twins Jamie and Danny Yeadon, 19, Simon O’Hanlon, 18, all of Bradford, and 20-year-old Michael Brogan, of Ilkley, pleaded guilty at Bradford Crown Court in December to unlawfully wounding Mr Dennis.

They were sentenced to 15 months in a young offenders’ institution by Judge Jonathan Durham Hall QC.

The defendants confessed to surrounding their victim, striking him with a branch and hitting him with fists and feet.

But the court heard Mr Dennis had been seen banging his head on the bar counter at The Sun Hotel in Shipley on the night of the attack.

A forensic pathologist said the self-inflicted blows could not be ruled out as a contributory cause of injury.

After the case, the victim’s father, Robert Dennis, said he was ‘disgusted’ with the sentences. He said it was impossible to say what the future would have held for his son.

West Yorkshire Police wrote to the Crown Prosecution Service, asking it to consider whether the sentences could be appealed.

A CPS spokesman said sentencing was a matter for the courts.

But he added: “In this type of case, where the injuries sustained are grave, and a weapon had been used, the sentencing range is between 18 months and three years, depending on the circumstances.

“In this case, in the light of the injuries and substantial mitigation put forward by the defence, the CPS has concluded that the sentence handed down by Judge Durham Hall was not unduly lenient and that there are therefore no grounds for appeal.” The court had heard Mr Dennis was a hard-working man, at the Asda store in Shipley, who had been drinking his worries away on that night.