Peter Sutcliffe, the Yorkshire Ripper, has begun a bid for release from prison.

His application to have a tariff set which could lead to parole was launched at the High Court in London.

A judge lifted a cloak of anonymity thrown over Sutcliffe, 63, as he conducted a preliminary hearing and gave directions for the tariff-setting exercise.

Previously referred to as "P" to protect his identity, a question mark remains over whether Sutcliffe will have to spend the rest of his life behind bars.

Now known as Peter Coonan, the lorry driver from Bradford was convicted at the Old Bailey in London in 1981 for the murder of 13 women, and seven counts of attempted murder, in Yorkshire, Greater Manchester and Lancashire.

He is currently being held in Broadmoor top security psychiatric hospital after being transferred from prison in 1984 suffering from paranoid schizophrenia.

Mr Justice Mitting, sitting in London, was deciding what form the tariff setting hearing should take, and what evidence should be admitted.

The judge was told there was new expert evidence on Sutcliffe's psychiatric state which could help his case for release on licence.

At the outset of the hearing the judge took away Sutcliffe's anonymity, saying: "It is now common ground this is part of the criminal process and must therefore proceed in the defendant's own name.

"The press are at liberty to report the fact that these proceedings concern Peter Sutcliffe/Peter Coonan."

Paul Bowen, appearing for Sutcliffe, indicated there had been an application to continue keeping his identity secret, but said: "We are no longer pursuing that application."

The Prime Minister said in February last year it was "very unlikely" Sutcliffe would be released.

It was on July 5, 1975, just 11 months after his marriage, that he took a hammer and made his first attack on a woman.

Sutcliffe believed he was on a "mission from God" to kill prostitutes - although not all of his victims were - and was dubbed the Yorkshire Ripper because he mutilated their bodies using a hammer, a sharpened screw driver and a knife.