The mother of murdered teacher Jane Longhurst has spoken of her dismay and horror that her daughter's killer might be given a retrial.

Graham Coutts was convicted of murder in February, 2004, by a unanimous jury. But a judgement in the House of Lords last week means he might be tried again because the jury were not given the option of convicting of manslaughter.

Since Jane's death, Mrs Longhurst has campaigned tirelessly against violent internet porn, after it emerged during the trial that for years Coutts had been looking at sick and depraved images on the web.

The part-time musician of Waterloo Street, Hove was originally sentenced to life. The minimum jail term of 30 years was reduced to 26 years at the High Court in January 2005.

Now his Lords appeal has been successful he might face a retrial.

Mrs Longhurst, from Reading, said she was shocked by the judgement which contradicted the earlier decision of High Court judges.

She said: "I was dismayed, horrified and rather angry. My feeling was that obviously the higher ranks of the legal profession wished there to be a change in the law and they have chosen to make Jane's case the pivot on which it goes.

"It doesn't smack to me of true justice at all. They want to make it mandatory to make all judges give the option of manslaughter in murder trials. I feel absolutely dismayed and gutted."

Mrs Longhurst attended the appeal in the High Court in December 2004 and 2005, when judges ruled there had been no mistake when the original trial judge had directed the jury to either acquit Coutts or convict him of murder.

She has now been told a retrial could begin as early as next April. It is unlikely to be held locally.

She said: "I fear there is a huge opportunity for taxpayers' money to be spent and for lawyers to make huge profits. It is terrible."

Jane, 31, a special needs teacher of Shaftesbury Road, Brighton, died on March 14, 2003. Sentencing Coutts in 2004, Judge Richard Brown said she was "the sort of person who enriched all those who came into contact with her".

Throughout the original trial Coutts, now 37, argued that death had occurred during consensual sex using asphyxiation with a pair of tights. Afterwards he kept Jane's body in a storage unit. It was found at Wiggonholt Common, near Pulborough, on April 19, 2003.

In their judgement last week, the five law lords thought it was not in the public interest for a jury not to be offered the option of convicting on a lesser charge.

Lord Bingham said: "While the murder count against the appellant was clearly a strong one, no appellate court can be sure that a jury, fully directed, would not have convicted of manslaughter."