It has been claimed the move would give Scottish judges increased powers to impose life sentences to those convicted of the most serious violent and sexual crimes, including the murder of a police officer.
Lifers in Scotland are currently eligible for release by the parole board when they have served the “punishment” element of their sentence.
This is different from England and Wales where courts have the power to effectively jail the worst offenders for the rest of their lives.
Tory justice spokesman Liam Kerr said: “We must give judges the ability to put the worst criminals behind bars for the rest of their lives.
“Judges south of the Border already have this power, it is time that Scottish judges did also.
“The worst offenders should be in no doubt that they face the severest consequences for their actions – jail for the rest of their lives.
“The SNP’s soft touch justice agenda has been letting down victims for too long. Giving judges this option will keep the public safer and give victims the justice they deserve.”
If someone is convicted of murder in Scotland at the moment, they will receive what is called a “life sentence”. Courts also have the option of imposing such a sentence for other crimes, including rape and sexual offences.
However, it does not mean those handed a life sentence will spend the rest of their lives in jail. Instead, the court will set a “punishment” part of a life sentence, which is the minimum time the offender must spend in prison before being considered for release on parole.
The remaining “security” part of the sentence can be served in the community.
In the most extreme cases, courts can impose an order for lifelong restriction (OLR) for criminals who, if at liberty, are considered to seriously endanger the lives, or physical or psychological well-being, of members of the public.
However, two prisoners with such orders were released in the past five years.
The proposed bill launched by Mr Kerr today comes after Aaron Campbell, 16, was granted leave to appeal the length of his sentence handed down for abducting, raping and murdering six-year-old Alesha MacPhail on the Isle of Bute last year.
Campbell will become eligible for parole after serving at least 27 years behind bars.
The situation is different south of the Border where English and Welsh courts have the power to impose “whole life orders” in certain circumstances, which do not allow the offender the chance to ever be released from prison.
But a Scottish Government spokesman said: “Scottish courts already have powers to impose a punishment part of a life sentence that can extend beyond the rest of a person’s life.
“We fully support Scotland’s courts having powers to ensure those who commit the worst crimes can face appropriate consequences for their actions, and the long-standing powers of the courts to sentence murderers and the most serious offenders to a period in custody that can extend beyond the rest of their life.”