A jury should have been offered the possibility of a manslaughter verdict in the case of a musician convicted of the murder of teacher Jane Longhurst, Law Lords heard yesterday.

Lawyers for Graham Coutts are petitioning the lords on a point of law at a two-day hearing on the basis that the lesser charge should have been left.

Edward Fitzgerald QC, for Coutts, said there was sufficient evidence of a lack of intent for alternatives to murder to have been offered to jurors at his trial.

Coutts, 36, of Waterloo Street, Hove, strangled 31-year-old Miss Longhurst, a special needs teacher originally from Reading, Berkshire, with a pair of tights in March 2003.

His trial at Lewes Crown Court heard he kept her body in storage for weeks before it was found burned on Wiggonholt Common, near Pulborough.

He admitted he had been there when she died but denied murder, saying her death was an accident during consensual sex.

Judges at London's Appeal Court rejected his appeal against conviction in January last year.

The main grounds of his appeal was a submission that the trial judge failed to direct the jury it was open to return a verdict of manslaughter.

Lord Woolf, the Lord Chief Justice, sitting with Mr Justice Creswell and Mr Justice Simon, ruled Coutts' conviction was safe. However, he said his case raised issues of "general public importance" fit for consideration by the House of Lords.

In front of Lords Bingham, Nicholls, Hutton, Rodger and Mance yesterday, Mr Fitzgerald said Coutts applied pressure to Miss Longhurst's neck with the intention of causing discomfort, but that the effects of his actions were greater than he intended.

He said: "It may be that whatever the rights and wrongs of the act itself, there simply wasn't the sufficient intent to kill or cause her grievous bodily harm and that would fit in with evidence from his previous girlfriends."

Mr Fitzgerald added that in every murder case, there is an "inherent possibility" of manslaughter where there is no malice aforethought.

He said the prosecution may have welcomed the "all or nothing" option of murder because it may have helped focus the jury's mind on the Crown's case.

But he said the decision whether to give the jury options other than murder rested with the judge.

"It isn't a distraction for the jury to be told what else is available," he said.

During Coutts' trial, it emerged he was obsessed with visiting sadistic pornographic websites showing violence against women.

Mr Fitzgerald said Coutts' "admitted conduct" may have compelled the jury not to allow him to go unpunished.

He called on the Law Lords to reverse the decision by the Court of Appeal and quash Coutts' conviction, which could force a retrial.

An "error of law" had been made when the trial judge failed to offer a manslaughter verdict, he said.

Mr Fitzgerald said: "The verdict of manslaughter should have been left on the basis of an unlawful act.

"By not leaving it, there was a natural misdirection on an error of law and it cannot be said that it wouldn't have made a difference to the verdict.

"We say the very fact there was a viable manslaughter alternative means it should have been left, and that by not leaving it, the judge exposed the appellant to the risk that the jury would think he should not go unpunished."

He said there was a "real possibility" Coutts was convicted on the basis the jury did not want to see him freed, having admitted responsibility for Miss Longhurst's death.

The Law Lords will hear today from John Kelsey-Fry QC, for the Crown, before reserving judgment for up to eight weeks.