Criminals caught red-handed who plead guilty will be rewarded with a one-fifth reduction in their sentence, senior judges have ruled.

The verdict by the Sentencing Guidelines Council means violent offenders will be able to ensure softer punishments even when there is no doubt of their guilt and a conviction is inevitable.

The Government had demanded the current one-third discount for those who plead guilty at the earliest opportunity should be slashed to zero in some cases where there is overwhelming evidence.

But the controversial council, headed by Lord Chief Justice Lord Phillips, said it should be only reduced to one-fifth. The change will take place from Monday.

Sir David Latham, a member of the council and vice-president of the Court of Appeal, said: 'Every defendant who is guilty should be encouraged to indicate that guilt at the first reasonable opportunity. That is the purpose of giving credit through reduced sentences.'

The system of rewarding early guilty pleas is designed to reduce the burden on the justice system. But last year John Reid and Lord Goldsmith, who were then Home Secretary and Attorney General, called for an end to the perk for criminals who clearly have no defence anyway.

It followed controversy over two paedophiles who won reduced sentences.

Alan Webster, who raped a baby, had his life term reduced by a third even though police had photographic evidence of the attack.

Craig Sweeney, who abducted a threeyearold, also had his life sentence cut by a third even though he was caught with his victim. It meant Webster could hope to leave jail after six years and Sweeney after five. The Sentencing Guidelines Council is a quango dominated by judges which has clashed repeatedly with ministers over sentencing for murder, burglary and other serious crimes. Lord Phillips suggested last autumn that long jail terms are 'barbaric'.

Under the new rules most of the original guidelines remain the same. Broadly, they say that if suspects admit an offence by the time they are taken to a police station or by their first court appearance, they are entitled to a third off their sentence.

If they admit guilt after a trial date is set, they can have a quarter off. If they plead guilty just before the trial starts or after it has begun, they can receive a tenth off. The only significant change is for cases involving overwhelming guilt.

Shadow Justice Secretary Nick Herbert said: 'Any reductions should be dealt with on a common sense, case-by-case basis. If necessary the discount should be zero.'