A musician convicted of murdering teacher Jane Longhurst has won leave to challenge a point of law which could lead to a retrial.

His victim's mother today expressed her disappointment and dismay at the latest legal move by her daughter's killer.

Graham Coutts, 35, of Waterloo Street, Hove, has been granted leave to ask the House of Lords to pronounce on a point of law in connection with his case.

Coutts strangled Miss Longhurst to satisfy his perverted sexual fantasies.

He kept 31-year-old Miss Longhurst's body in a box in his shed for 11 days before moving her to a storage unit in Brighton for a further two weeks.

The special needs teacher's burning body was found on Wiggonholt Common, near Pulborough, on April 19, 2003.

Coutts, who is obsessed with internet images of necrophilia and strangulation sex, denied murder but was found guilty by a jury at Lewes Crown Court in February last year and sentenced to life imprisonment.

Coutts claimed Miss Longhurst died accidentally when he tied a pair of tights around her neck during consensual sex.

He lost his appeal against conviction earlier this year but his minimum sentence was cut from 30 to 26 years.

If the Lords finds in his favour this time, there is a possibility they could rule the case is worthy of a retrial.

The issue at the centre of the action is whether Judge Richard Brown should have given the jury at Coutts' trial the alternative of manslaughter before it retired to consider its verdict.

The Appeal Court rejected refused permission for Coutts to appeal to the House of Lords.

But the Appeal Court certified the case raised issues of public importance which enabled his defence team to take the case to the House of Lords.

Gary Perry, of the Crown Prosecution Service, said: "This is not an appeal against conviction or a retrial.

"He has been granted leave to take his codified question to the House of Lords. One possible outcome is that he will be granted a retrial."

No date has yet been set for the hearing.

Miss Longhurst's mother Liz, 73, said she felt confident Coutts would lose his latest legal action and stay behind bars in prison.

She said: "I am really rather dismayed but I still feel pretty confident there is no way he can possibly succeed." She questioned how the murder of her beloved daughter could possibly be manslaughter.

She said: "If it was, why was he not immediately dialling 999? But he didn't."

Mrs Longhurst, who has campaigned for violent sex sites on the internet to be banned, said she was disappointed the legal action continued so long after her daughter's death.

She said: "I thought we had reached the end. Apart from everything else, all this is costing the taxpayers. I don't think it is necessary at all.

"The first trial was scrupulously fair. I certainly don't think having a retrial would further the cause of justice. I am sure the right thing has been done."