Some of Britain's leading judges warned that an impending shake-up in sentencing guidelines could lead to an increase in prison overcrowding, it was reported.

Writing in the Times, Judge Keith Cutler, vice-president of the Council of Circuit Judges, said the Sentencing Council which comes into effect next month, could actually increase judges' use of custody.

He said: "Judges tend to use their discretion to operate towards leniency.

"We fear that the requirement 'must follow' will erode judicial discretion and that will lead to heavier sentences.

"The hope was that the existence of the council would reduce the use of custody.

"But in the present climate it is unlikely to issue guidelines that are more lenient. Imagine the public outcry."

The Council of Circuit Judges, representing 600 judges in England and Wales, told the paper they would be left with no freedom to fit punishments to the specific circumstances of a case.

The Sentencing Council for England and Wales, was introduced with a strengthened remit to promote consistency and predictability in sentencing.

A Ministry of Justice spokesman said: "There will not be an American-style sentencing grid or matrix.

"Judges will still have the discretion and flexibility to give the sentence they think most appropriate.

"Judicial discretion in sentencing in individual cases is the cornerstone of our justice system. We are not going to change that."