BRITAIN’S top judges are to provoke a confrontation with ministers by announcing plans that could see murderers serving as little as seven years in prison.

Draft guidelines, leaked to The Sunday Times and to be unveiled tomorrow by Lord Woolf, the lord chief justice, will allow crown court judges to apply a “reduction principle” that could see the new minimum 15-year murder sentence cut by “greater than one-third”.

Killers who “make a particularly early confession of guilt” or show “absolute candour” in co-operating with police could see years knocked off their sentences. With remission, this could allow them to be released after as little as seven years.

In what is effectively a “plea bargain”, the aim of the proposals from the Sentencing Guidelines Council is to save court time and money as well as enabling victims and witnesses to avoid the trauma of giving evidence.

This weekend, however, the move provoked accusations that a liberal judiciary has gone soft on the most serious offence, and is thwarting the intentions of parliament.

David Davis, the shadow home secretary, said: “We have told (David) Blunkett (the home secretary) time and again that parliament, not the judiciary, should set the sentencing guidelines. These latest proposals demonstrate why.

“The dramatic reduction of the minimum sentence for murder makes a mockery of Blunkett’s claims to be tough on serious crime. A mere six or seven years for murder would be a joke if it were not a tragedy.”

Blunkett introduced the new minimum 15-year sentence last year as a cornerstone of his criminal justice reforms. Before that, the average time served by killers was just over 11 years.

“The new sentencing principles for murder will help to increase the public’s confidence in the criminal justice system’s ability to deal appropriately with these most serious crimes by providing adequate punishment for the guilty and adequate public protection,” Blunkett said at the time.

“These principles arise not out of any lack of confidence in the judiciary but out of the special significance of the offence of murder and the need to ensure that the framework for the sentencing of murder is set by parliament and incorporates an element of democratic accountability,” he added.

The move came despite a direction to all judges from Woolf a year earlier that the new minimum should be 12 years. Woolf, whose liberal views on crime and punishment have long angered ministers, was infuriated by what he saw as an attempt by Blunkett to “fetter” the independence of the judiciary.

Woolf has in the past urged prison to be seen as a last resort and called for community penalties to be considered as an alternative.

When the Sentencing Guidelines Council was set up, Woolf told MPs that it would not pander to “public clamour” or bow to pressure from parliament. He said the council would herald the end of “knee-jerk” legislation by MPs on sentencing.

The council was established as an independent body last year to make sentencing more consistent and transparent.

It will issue guidelines on sentencing to all courts for the estimated 2,000 offences on the statute book. The council is chaired by Woolf and includes Lord Justice Rose, vice-president of the Court of Appeal, Peter Neyroud, the reform-minded chief constable of Thames Valley police, lawyers and victims’ representatives.

Westminster insiders say Woolf has used the council to effectively return sentencing to an even more liberal version of what existed before Blunkett’s criminal justice legislation introduced the new 15-year minimum.

Observers say the new “softly softly” approach represents Woolf’s revenge for his humiliation by Blunkett during the row over sentencing for murderers last year.

A conference of top judges at Warwick 10 days ago was told by a leading sentencing expert that the new guidelines could mean murder sentences of as little as six or seven years being handed out.

However, that interpretation was disputed by Kay Taylor, Woolf’s legal secretary. She said the effect of the proposed reduction in jail sentences for murderers could in some cases be partly mitigated by other practice directions issued by Woolf.

Woolf has made no secret of his fears that longer sentences for murder would have a knock-on effect on the overcrowded prison system, with increased sentences for other offences. The prison population of England and Wales is at a record high of 74,489 and Ken Macdonald, the director of public prosecutions, has backed Woolf, saying Blunkett’s sentencing regime for murder would make the situation much worse.

“This would have an extraordinary effect on the prison population, but particularly on the long-term prison populations,” he told the all-party parliamentary group on penal affairs last year.

Under Blunkett’s law, murderers should be classified in three tiers. Terrorists responsible for atrocities, mass murderers and child killers will serve their entire lives in jail.

The law stipulates a 30-year minimum for serious murders such as killing a policeman in the line of duty and a 15-year minimum for all other murders. Legal experts say the new guidelines — allowing a reduction of one-third — cover all three categories of murder.