CONSERVATIVE plans to let Scotland’s worst criminals die in jail have been emphatically rejected by MSPs.

Holyrood’s four other parties lined up against the proposal for “whole life custody sentences” when it was put to a vote in a Tory-led debate.

It followed Tory justice spokesman Liam Kerr publishing a detailed plan last week to bring Scots law into line with England and Wales on the issue.

Although Scottish courts can sentence offenders to life, all prisoners are automatically eligible for parole once the so-called “punishment” part of their sentence has passed.

Under current guidelines this would be around 20 years for the murder of a child.

The Tories’ proposed Whole Life Custody (Scotland) Bill would give courts the option to sentence offenders aged 21 or over for the rest of their life for particular crimes, including multiple murder, serial rape, and sexual offences against children.

To comply with the European Convention on Human Rights, whole life prisoners would still have been eligible for compassionate release.

The SNP Government initially said it would consider the proposal, but community safety minister Ash Denham said she was not persuaded.

She cited the case of World’s End killer Angus Sinclair as an example of Scottish judges already being able to imprison people for the rest of their natural life.

READ MORE: 37 more years in jail for serial killer linked to 10 deaths

The serial killer and rapist died in March aged 73 after being sentenced to a record 37 years in 2014 for the murder of teenagers Christine Eadie and Helen Scott in Edinburgh in 1977.

Ms Denham said Sinclair could not have applied for parole until he was 106 years old.

But Mr Kerr said his death behind bars was “an accident, not by design”, and if he had been given the same sentence immediately after the murders he might now be out of jail.

He said: “The incontestable fact is this - Scottish courts cannot by law guarantee that the worst criminals will not be let back on to our streets.”

Labour MSP Pauline McNeill said Mer Kerr’s Bill was “a meaningless stunt”, adding: “Judges can extend the punishment beyond the likely remainder of a prisoner’s life. It has happened on numerous occasions.”

Mr Kerr hit back: “This isn’t a stunt, I’ve been working on the guts of it for the last two years. A stunt is not something you pull out after two years of very difficult work.”

MSPs voted 88 to 28 to completely rewrite the Tories’ motion backing whole life sentencing powers to say judges could already impose a punishment part longer than a person’s life.

READ MORE: World's End killer Angus Sinclair dies in prison aged 73

It means Mr Kerr’s Bill is doomed as it lacks cross-party support.

After the defeat, he said: “Judges should have the ability to put the worst criminals behind bars for the rest of their lives.

“Victims and their families are quite clear that those who commit the worst violent and sexual crimes should face jail for the rest of their lives.

“The other parties must explain why they are opposed to giving victims this certainty.”

Scottish Liberal Democrat MSP Liam McArthur said: “Life sentences already exist in Scotland.

“For the Tories this has been an exercise in political posturing, not a serious attempt to reform sentencing.”