The family of a teacher strangled to satisfy her killer's macabre sexual fantasies has won MPs' backing to close down hardcore internet porn sites.

Brighton Pavilion MP David Lepper joined Labour colleagues in tabling an Early Day Motion yesterday calling for a change in the law in the wake of the Jane Longhurst murder trial.

They want ministers to review the Obscene Publications Act so hardcore sites promoting necrophilia and violence against women will be closed down or filtered.

Musician Graham Coutts visited violent sex sites to satisfy his sexual fantasies before murdering Jane, a 31-year-old special needs teacher from Brighton.

The Argus reported yesterday how Coutts's former partner, teacher Lisa Stephens, backed the calls for a ban.

She did not know he trawled through the internet for images of necrophilia, rape and torture and believes they paved the way for murder.

Ms Stephens, who gave birth to their twin boys as Coutts awaited trial, said: "Graham channelled his sexuality along the wrong route and that is dangerous.

"Rape and necrophilia web sites are easy to access.

"I want the sites shut down, if not for adults then at least for children.

"There was a seed of thought in Graham's head already and he used the internet to explore and expand it."

The campaign is also being spearheaded by Jane's mother, Liz, 72, and partner Malcolm Sentance.

Martin Salter, MP for Reading, where Jane's family live, has written to Home Secretary David Blunkett asking for talks.

He said: "It is appalling that commercial organisations are able to make huge profits distributing material that feeds sick and perverted sexual fantasies about necrophilia - fantasies that eventually lead people like Graham Coutts to commit a most foul and horrific murder."

However, Mr Lepper said a change in English law would not be enough.

He said: "We also need international co-operation because sites in this country can be closed down but it is difficult to stop sites based in other countries.

"I am totally in support of this, however, and we are hoping a decision will be taken quickly."

Hove MP Ivor Caplin said he could not comment on Early Day Motions because he was a member of the Government.

However, he said: "The Jane Longhurst murder has been a dreadful event and I think investigations need to be carried out so we can understand how such a terrible murder has taken place.

"I would back a wide-ranging investigation into the sites."

Moves towards a change in the law have also been backed by Sussex Police.