Courts have been ordered to set aside rules that were due to come into force on Monday allowing fines and community penalties to be imposed on people caught with knives, because of the “national problem” over knife crime.

Any adult caught with a knife who pleads not guilty is likely to be sentenced to a minimum three months in jail if convicted, after a last-minute U-turn on new sentencing guidelines.

The Sentencing Guidelines Council placed the rules - which include increasing sentences for dangerous knife possession from six weeks to six months - unannounced on its website yesterday.

The decision not to implement them marks an important change in approach to the growing problem of knife possession.

The change emerged yesterday, only 72 hours before the sentencing guidelines for 30,000 magistrates were scheduled to come into force throughout England and Wales.

The starting point for a knife offence, magistrates have now been told, should be a three-month jail term for a first-time adult offender pleading not guilty. In more serious cases, in which a knife is used in dangerous circumstances, not just to cause fear, magistrates have been told that the starting point should be six months in jail. The most serious cases will still be sentenced at the Crown Court, where the maximum sentence for possession of a knife is four years.

The decision to alter the guidelines, and the way in which it was disclosed, is expected to raise further doubts about the council's approach to publicising the punishments for knife offences.

The announcement took the Ministry of Justice and the rest of the Government by surprise, but comes after criticism of the original guidance issued this year.

Seventeen teenagers aged between 14 and 19 have been stabbed to death in London this year, according to Scotland Yard. The latest stabbing victim to die was a woman, 23, who was attackedyards from where she was having a meal with her boyfriend in Battersea.

Yesterday the Sentencing Guidelines Council said that its new message to magistrates was a reflection of a ruling by the Court of Appeal in May. The court said that for the time being sentencers should focus on reducing crime and protecting the public.

The Sentencing Guidelines message to magistrates setting aside the new guidance because of public concern over knife crime said: “Significant attention has been paid to this guideline ahead of it coming into effect as a result of the current focus of the media on violent crimes involving knives.”

It advised magistrates that sentences should be applied “at the most severe end”. It added: “When the current concerns have been overcome, courts will be notified that the approach should return to the guideline as published.”

The note said that more cases would be sent to the Crown Court for sentencing, which is likely to mean more offenders being given longer jail terms. It did not explain why it had taken until three days before the guidelines were supposed to come into force for the council to issue a formal note telling magistrates to set them aside for the time being.

A spokeswoman at the Sentencing Guidelines Council said that it had reacted because of concern about the extent of knife crime.

She said said that the council was able to urge courts to adopt a tougher approach for a period of time where there is “great public concern” about the prevalence of particular crimes.

Yesterday's move by the Sentencing Guidelines Council comes after demands from ministers that it rethink its original guidance. Tony McNulty, the Police Minister, condemmed the recommendation of fines for possessing a knife and demanded that the council reconsider its position to take into account the broader national view that knife crime is “very, very serious and needs to be treated accordingly”.

Jack Straw, the Justice Secretary, said last month that nothing could be done to stop the guidelines coming into effect on Monday but said that a stock take of how they operated would be conducted.

The Sentencing Guidelines Council was set up to give “authoritative guidance” on sentencing to the courts with the aim of getting more consistent sentencing throughout the country.

Living by the blade

129,840 offences, 6 per cent of all violent crime, involved a knife last year, according to the British Crime Survey

22,000 attempted murders, robberies and woundings involving a knife were recorded by police in England and Wales in 2007-08. Half of them were in London, Greater Manchester and the West Midlands

4 years in jail is the maximum sentence for possession of a knife

18 the minimum age at which someone can buy a knife

17 teenagers killed with a knife in London this year

Sources: Home Office; Metropolitan Police

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