Andrews, who was the Duchess of York's dresser and assistant for nine years, is serving a life sentence for killing her lover.

Something has caused the abuse to come out

Vera Baird QC

The 35-year-old has been granted permission to challenge the conviction on the grounds of diminished responsibility.

The full appeal hearing, to be heard later, will focus on alleged sexual abuse when she was a child.

Andrews, who lost her job as a royal aide when she was made redundant in 1997, did not attend the leave to appeal hearing before Mr Justice Field at the Court of Appeal in London.

Denial

She was found guilty of killing her boyfriend Tom Cressman at a trial at the Old Bailey in May last year.

The ex-royal aide had denied murdering the 39-year-old in bed at their �400,000 home in Fulham, west London, in the early hours of 17 September 2000.

Andrews hit him over the head with his cricket bat before stabbing him in the chest with a kitchen knife.

She was said to be motivated by revenge, after Mr Cressman refused to marry her.

Tom Cressman refused to marry Andrews

Andrews testified that she stabbed her boyfriend accidentally during a struggle as he tried to rape her in the early hours of September 17, 2000.

A psychiatrist who visited Andrews in jail after the trial concluded she was suffering from diminished responsibility when she killed Mr Cressman.

Vera Baird QC, for Andrews, told the appeal court that the "strength" of the appeal case lay in "fresh psychiatric evidence" of sexual abuse.

Collapse

At the original trial, Andrews collapsed in the dock when asked about abuse.

Miss Baird told the court that her client's ability to talk about it had since been "unlocked".

"Something has caused the abuse to come out," she said.

"(And it) changes the complexion of this woman's psychiatric structure."

The judge warned Miss Baird that he was "sceptical".

"You must expect that the court on appeal is going to need a deal of persuading whether Miss Andrews should have this second opportunity," he said.

"But I think you have sufficiently established a degree of arguability to persuade me you should have leave."