A worker who struck a colleague over the head with a scaffold pole at a Milton Keynes building site has been put behind bars for 12 years.
Kieran Fowler, 23, caused his victim to spend seven weeks in a coma, Luton Crown Court heard.
He denied causing GBH with intent but was found guilty after a four day trial.
The court heard Fowler became involved in an altercation with the 43-year-old victim while they were working together on a site in Rowditch Furlong at Blakeslands in October last year.
He struck the victim over the head from behind with the scaffold pole, causing him to fall to the floor.
Fowler fled the scene on foot but was arrested the same day.
The victim was airlifted to the John Radcliffe Hospital, Oxford. He sustained life changing injuries, including multiple fractures to his face and skull which required surgery.
He spent seven weeks in an induced coma to allow his head injuries to heal.
Co-defendant, Alan Fowler, aged 49, was found not guilty by a unanimous jury of grievous bodily harm with intent.
Investigating officer, Detective Constable Ian O’Bryne said: “The sentence given to Kieran Fowler reflects the severity of the incident during which the victim sustained horrific injuries. The length of the sentence goes a long way in helping the victim recover from the memories of the attack.
“During the incident Kieran Fowler became involved in a verbal argument with the victim. The case serves as a harsh reminder to the public not to take the law into your own hands.
“I would like to thank the victim who has shown great bravery during the trial, as well as all the witnesses and members of the public who came forward with vital information.
“I would also like to thank all officers and staff at Thames Valley Police who worked on the case, as well as the Crown Prosecution Service for bringing the case to trial.”