The Conservative leader cited the case of a rape victim as she demanded an end to the "scandal" of automatic early release for prisoners.

Ruth Davidson urged new First Minister Nicola Sturgeon to scrap the "absurd" rule which can see some inmates get out after serving half the jail term imposed on them.

She said current plans to change the system were inadequate and "barely scratch the surface" of the problem.

"This is not a resource issue, this is a moral issue," she told MSPs at Holyrood.

Ms Davidson spoke out in light of the case of rape victim Erin O'Neill, 25, who recently waived her right to anonymity to tell her story.

In a newspaper, she revealed how she later discovered that the man convicted of attacking her, Ross Wright, had been released from prison following a previous violent assault, having served only half his sentence.

The victim told the Daily Record: "Wright should have been behind bars. But he was allowed loose on the streets to rape me."

Ms Davidson, who cited the article in the Scottish Parliament, praised Ms O'Neill's bravery in coming forward.

The Glasgow MSP said: "Ross Wright was freed because of the absurd rule of automatic early release. We've been calling for that law to be scrapped for a number of years.

"The Scottish Government has now published plans to address this, but they will only cover a derisory number of cases. Doesn't the First Minster see that these plans are utterly inadequate?"

Ms Sturgeon also paid tribute to Ms O'Neill's bravery and said she would be happy to meet her to discuss the "extremely important issue".

She said a Bill has been released into Parliament, which would end the entitlement to automatic early release for the most serious and dangerous of offenders.

She said: "I would point out... that automatic early release was introduced by the Conservative government through 1993 legislation and it was left in place by the entirety of the Labour/Liberal Democrat administrations here in Holyrood.

"I certainly am in agreement that this is a change that needs to be made."

The First Minister said it would be the job of parliament to scrutinise the proposals and, if appropriate, for MSPs to bring forward suggested amendments.

Ms Davidson said the Scottish Government's Bill and the current plans contained in it "barely scratch the surface of what we are talking about".

She said new figures from the Scottish Parliament's information service show that last year the plans contained in the Bill would have applied to just 107 sexual offenders and 24 other violent criminals. Those 131 offenders represented less than 1% of the more than 14,000 criminals sent to jail last year, it was claimed.

Ms Davidson said: "The Government has previously argued that ending automatic early release is a resource problem. This is not a resource issue, this is a moral issue. Criminals need to know that unless there is an exceptional reason not to, you will serve the sentence that the judge hands down."

Addressing Ms Sturgeon, she added: "If she does think that there is some common ground between us, can we work together to end this scandal for good?"

Ms Sturgeon, taking part in her first question time since becoming First Minister, said she would work with other MSPs and added that she would be open minded about seeing if the proposals contained in the Bill could go further.

Referring to the previous Tory government at Westminster, she said: "That Conservative government did not build a single new Scottish prison during their 18 years in power.

"By contrast, this Government has invested over £528 million in the prison estate since 2007/08.

"We are taking the decisions that address what Ruth Davidson described as resource issues in our prison estate, which then make it possible to introduce the kind of reforms that she's calling for today.

"I think we're going about this the right way, in a reasonable way."

Liberal Democrat leader Willie Rennie later challenged Ms Sturgeon to address "failures" within the wider justice system.

He said: "Can I encourage her to look early doors at the issues around justice - mishandling of corroboration, the routine arming of police and stopping and searching of children - things I have raised week after week in this chamber.

"Everyone knows (Justice Secretary) Kenny MacAskill is going but which of his policy failures are staying?"

He claimed stopping and searching is now seven times higher in Scotland than the rest of Britain, with "thousands" of children being searched each week.

The First Minister said her door is open for "sensible" discussion around policy.

She said: "I can't promise I'll agree with him on everything, but where we can find common ground I am certainly willing to try to find it."

Ms Sturgeon also claimed there is much to be proud of in the justice system.

She pointed to the Government's commitment to having 1,000 extra police officers, recorded crime being at a 40-year low, a drop in the risk of being a victim of crime and a fall in violent crime.

"I think the record of this Government on justice issues is a very good one and a very strong one," she said.