BBC Correspondent David Sillito reports on Hindley's appeal

David Pannick QC said the 32 years she had served was not long enough for such a "pitiless" killer.

Hindley, 56, is asking the Court of Appeal to overrule the decision of successive home secretaries to deny her parole.

Supporters say Hindley, pictured in jail, has changed

Her lawyers say the imposition of a "whole life" tariff is against natural justice since the trial judge recommended she serve 30 years.

Shocking crimes

But Mr Pannick said: "The passage of time - 32 years - cannot erase the truly horrific conduct with which this appellant was found guilty."

He rejected claims by Hindley that she was the victim of "intimidation and corruption" by her co-defendant Ian Brady, now 60.

Jack Straw: Life should mean for life

Mr Pannick said: "The Secretary of State simply does not accept that the account now given by the appellant, even if true, provides mitigation which could reduce the proper tariff below that of whole life."

Hindley, who was convicted of killing 10-year-old Lesley Ann Downey and Edward Evans, 17, is held at Highpoint Prison in Suffolk. She has subsequently admitted playing a part in the murders of Keith Bennett, 12, and Pauline Reade, 16.

Their victims were buried on Saddleworth Moor, on the edge of the Peak District overlooking Manchester.

'Murder under duress'

Hindley's lawyer, Edward Fitzgerald QC, said on Monday she had been throttled and raped by Brady and her family had been threatened.

Mr Pannick said Hindley's part in the murders of Lesley Anne Downey and Edward Evans was "pitiless".

Ian Brady...insists Hindley was his willing accomplice

She helped lure them to their deaths, he said, and had earlier assisted Brady to dispose of the body of John Kilbride, 10.

Mr Pannick said: "This is not a case where someone has forced her at knife point, or whatever, to carry out that specific act."

Last year the Court of Appeal, led Lord Chief Justice Bingham rejected her lawyers' arguments.

'Life means life'

The three judges ruled that home secretaries had the power to decide that a life sentence can mean life.

But, allowing her leave to challenge their ruling, he did not rule out that one day Hindley could be released "in exceptional circumstances".

The case has repercussions for many of Britain's most notorious killers. Rose West, Dennis Nilsen and Peter Sutcliffe are among those who have also been told they will never be freed.