A jury has cleared a roofer of wounding charges after he slashed a workmate who attacked him in their shared digs.

Gordon Shaw said he had been asleep at his rented home in Fishponds Road when Russell Parker came back from the pub and woke him up, asking for cannabis.

He told Bristol Crown Court he refused to give Mr Parker any more of the drug and a row culminated in Parker attacking him.

Mr Shaw, 57, who was working with his housemates on a city centre building project at the time, slashed Mr Parker's arm, neck and ear as the pair tussled, the jury heard.

But he said he had grabbed his work knife as he was being attacked and had no idea he had cut his workmate during the brawl.

He denied wounding with intent to cause grievous bodily harm, as well as an alternative charge of unlawful wounding in February.

A jury of eight women and four men took twenty minutes to find him not guilty of both charges yesterday.

Mr Shaw said when he refused to hand over any cannabis Mr Parker became agitated, slapping his forehead before shoving his head against a wall.

He told the jury: "I felt a bit dizzy and shocked. I picked up a chair and I smashed the chair on the floor. I said 'Come on big man, if you're going to do it'. I was angry and a bit afraid.

"I didn't have the bottle to go to him. He came towards me, I went to hit him with the bit of wood but I missed him."

Mr Shaw described how a workmate separated them but they continued to trade banter and he heard Parker say: "I swear to God I'm going to knock that old man's head off in the morning."

He told the court: "I don't know why I did it but I said: 'If you're going to do it, come and do it.' Then he came in and he was on top of me, ranting and raving. There was spit all over me, he put his arms across my chest and I couldn't breathe.

"I was starting to see stars a bit. I brought my knife out; the intention was working out how to get him off of me. Then he said 'He's cut me, he's cut me'. I swear I did not realise I cut him."

The jury heard that, having been cut, Mr Parker was taken to hospital and received 14 stitches to his wounds.