Criminals convicted of attempted murder should serve as little as 40 per cent of the sentence that would have been imposed if they had successfully claimed a life, sentencing advisers said today.

The Sentencing Guidelines Council, which chaired by Lord Phillips of Worth Matravers, the Lord Chief Justice and most senior judge in England and Wales, published a consultation paper on punishment of a wide range of assaults.

In a case of attempted murder the maximum discount from the sentence that would have been imposed for murder should be 60 per cent, the paper said.

Currently, the Court of Appeal suggests a reduction of 50 per cent in the most serious cases, it added.

An offender who believed they were committing an ?act of mercy? may be entitled to a lower sentence, the paper went on.

The starting point for sentencing an offence of assaulting a police officer should be 18 weeks? custody where an injury was caused, although it could go as low as a community order, the paper said.

A ?spontaneous? assault on a PC which caused no injury could be dealt with by a fine or a medium-length community order, it added.