A twenty-six-year-old cable layer was jailed for life yesterday for the murder of the man he found in bed with his mistress.

Robert Sanderson was also sentenced to three years for a brutal attack on his lover by punching and kicking her and striking her with hockey sticks.

There were emotional scenes at the High Court in Airdrie when the jury of seven men and seven women returned their verdicts after an eight-day trial.

Sanderson's mother, Marlene, 48, was led sobbing from the court.

Family and friends of murder victim David Allison, 36, wept and hugged each other after Sanderson was sentenced.

The Scottish Power cable layer, who had denied all charges, winked at his mother and gave her a thumbs-up sign as he was led away.

Seven police officers were positioned around the court as the jury returned their verdict and the judge, Lord Dawson, sentenced Sanderson.

It was alleged that Sanderson attacked Mr Allison after he found him in bed with his mistress, primary school teacher Mrs Shona Fowler, at Lilybank Avenue, Muirhead, on October 27 last year.

He was found guilty of repeatedly punching and kicking Mr Allison on the head and body, compressing his throat with his hands, and repeatedly hitting him on the head and body with hockey sticks.

Medical evidence was that Mr Allison, of Slakiewood Avenue, Mount Ellen, Lanarkshire, had a total of 133 injuries all over his body, including six lacerations to his head which were consistent with being caused by blows from a hockey stick.

However, medical experts said that although Mr Allison had a fractured skull and blood was bleeding into his brain, he in fact died when his throat was compressed.

Expert pathologists said the force with which Mr Allison's throat was compressed was so powerful that two thyroid cartiledges snapped, causing him to asphyxiate within a few minutes.

The pathologists also said that the blows to his head were a contributory cause of death.

Sanderson was found guilty of assaulting Mrs Fowler, 35, to her severe injury, permanent impairment, and disfigurement.

The jury's verdict was unanimous on that charge but was a majority verdict on the murder charge.

Sentencing Sanderson, Lord Dawson said the attack on Mrs Fowler was ''a very serious, brutal attack'' and he sentenced him to three years alone for that crime.

Lord Dawson said that in respect of the murder charge there was only one sentence he could impose and that was life imprisonment..

The court had been told that Mrs Fowler and Sanderson, who lived with his parents in Moodiesburn, Lanarkshire, broke off a four-year relationship to see Mrs Fowler regularly and ''get her out of his system''.

However, Mrs Fowler had told the court that her relationship with Sanderson had become ''an on-off affair'' and that on the night of the incident he had not turned up as arranged.

The mother of two young children said she went to the Muirhead Inn and was drinking double vodkas and chatting to her friend, Mr Allison, before they went back to her house.

She remembers nothing of the actual attack in which her teeth were shattered, nose broken, ear drums damaged, and she was severely bruised.

Sanderson had lodged a special defence of self-defence and a special defence of incrimination, stating that if a murder had been committed it had been by Mrs Fowler.

He claimed he saw Mrs Fowler standing over the unconscious Mr Allison, striking him with a hockey stick.