An argument broke out in The Messenger pub, in Covingham Square, at around 11.30pm on Friday night (19 October 2018).
The victim, a man in his 20s, was approached by two men who are known to him, who shouted and one of them grabbed him around the throat.
Just after midnight he left the pub to drive home, but was followed into the car park and struck over the head with a glass bottle.
The victim has received hospital treatment for a severe cut to the side of his head, which has resulted in him losing the top of his ear.
Detective Sergeant Scott Anger, from Swindon CID, said: “This was a nasty assault which has left the victim with a serious injury which will require ongoing medical treatment.
“Although he has been discharged from hospital he will need to return for specialist care and possibly surgery in the future.
“We want to speak to anyone who was in the pub at the time of the initial argument, and anyone who was in the overspill car park to the pub and witnessed the assault with the bottle.
“The victim has told us about a man in a red jacket who tried to help him, and we believe this man could be a key witness.”
Two men, aged 21 and 25, have been arrested on suspicion of causing grievous bodily harm, and have been released under investigation while our enquiries continue.
Anyone with information is asked to contact Det Sgt Anger on 101, quoting crime reference 54180099470. Alternatively you can call Crimestoppers anonymously on 0800 555111.
