Home Secretary David Blunkett has announced plans to introduce tougher sentences for murder. It will mean that in more cases, a life sentence will mean that the killer really does spend the rest of his or her life behind bars.
But the proposal is causing controversy in legal circles, with many judges said to be unhappy about what they see as political interference in the sentencing process.
BBC News Online correspondent Peter Gould considers how the new system of minimum sentences will operate.
Who does the home secretary want to lock up for life?
Mr Blunkett says a "whole life" sentence should be the normal punishment for any adult convicted in the most serious cases of murder. That would include children who had been abducted, or subjected to an attack of a sexual or sadistic nature.
This category would also include multiple murders where there was a high degree of premeditation, abduction, or any sexual or sadistic element. Terrorists who kill, and any offender previously convicted of murder, would also be liable to spend the rest of their life behind bars.
Can some other killers also expect to serve longer sentences in future?
Yes. The intention is to have a second category of murder with a minimum prison term of 30 years. This sentence would be imposed in cases where a police or prison officer was killed in the line of duty, or the murderer used a firearm or explosives.
It would also take in murders committed for financial gain...for example, during a burglary or robbery, or contract killings. This category would also include murders motivated by the race, religion or sexual orientation of the victim, and murders committed to defeat the ends of justice, such as the killing of a witness in a court case.
Any single murder with a sexual or sadistic element would also attract a 30-year minimum sentence, as would multiple murders not covered by the "whole life" category.
What about cases that do not fit into these two categories?
In all other cases of murder, the starting point will be a sentence of 15 years, which can be increased by judges in the light of individual circumstances. Offenders aged 17 or under will be included in this category, but those aged 18, 19 or 20 will be subject to the 30-year minimum if the crime meets the criteria.
How closely will judges have to follow these principles?
Judges will still be able to exercise discretion in the sentences they hand down. However, they will have to give an explanation - in open court - if they depart from these principles.
They are being reminded that the attorney general already has the power to intervene over "unduly lenient" sentences, so he will be able to challenge any sentence that is not seen to meet these new requirements.
Is this an attempt by the home secretary to re-establish his powers after efforts to end his role in the sentencing process?
In recent years, successive home secretaries have faced legal challenges after increasing the "tariff" or minimum sentence to be served by a number of killers. In a key decision last year, European judges ruled that keeping prisoners locked up in this way was a denial of their human rights.
The House of Lords then said that the way in which the home secretary set the sentence in murder cases did not comply with European law. It was after these important decisions that Mr Blunkett announced that he would be drawing up a framework for judges.
So what do the judges make of Mr Blunkett's new plan for minimum sentences?
Some see it as a threat the independence of the judiciary. The crime of murder does of course carry a mandatory sentence of life imprisonment. But judges think they, and they alone, should decide how long a prisoner actually spends behind bars before being considered for parole.
They feel that having listened to all the evidence, they are in the best position to determine the sentence that fits the crime. So they remain opposed to what they see as any attempt by politicians to intervene in the sentencing process.
So does Mr Blunkett think the judges have gone soft on murderers?
He says he shares public concern that some criminals, found guilty of very serious crimes, seem to be spending a relatively short time behind bars.
He points out that when Parliament voted to abolish the death penalty, it intended to introduce a strong alternative. So prison sentences for the most horrendous crimes must reflect the need to punish the offender, and send a clear signal that such crimes will not be tolerated.
He says that for the first time Parliament will now set out a framework for judges that will ensure that the sentences served by murderers reflect the seriousness of their crimes. The aim, he says, is to provide "clarity, consistency and confidence" in the sentencing of such offenders.