The legal framework underpinning the punishment of offenders in England and Wales is currently spread across more than 1,000 pages and stretches back as far as the 1300s.
Following a consultation, the Law Commission will today (Nov 22) unveil details of an overhaul that will mean anyone convicted should be sentenced under a simplified and modern sentencing code.
The body, which advises the Government on legal reform, says the measure would mean judges are no longer required to search back through layers of old law.
This would decrease the number of unlawful sentences handed out, avoid unnecessary appeals and reduce delays, according to the commission.
Law commissioner for criminal law Professor David Ormerod QC said: “Current sentencing laws are simply not up to standard.
“The public expect clear, transparent and most of all fair judgments. Far too often this is not the case.
“Our reforms will save time and money and make the law clearer and easier to apply.”
A report from the commission says the law governing sentencing procedure is “very complex and technical”.
At one time, courts had only a small number of sentencing orders to consider but the volume has surged, particularly in the last 30 years.
Research into sentencing law in force in August 2015 found it ran to more than 1,300 pages and contained provisions dating back to the Justices of Peace Act 1361.
The unnecessary complexity of legislation has led to a disproportionate number of errors and unlawful sentences, according to the commission.
It pointed to a 2012 study which found that, from a sample of 262 cases considered by the Court of Appeal criminal division, 95 - or over a third (36%) - involved unlawful sentences.
Outdated language and the need for judges to examine historic versions of sentencing law also give rise to inefficient court procedures, the commission warned.
Its report said: “A system in which delays and unnecessarily incurred costs are prevalent results in other cases being delayed, witnesses and victims having to wait around at court and is a drain on scarce public funds.”
The body is recommending a “clean sweep” of old sentencing law so that courts no longer have to refer to historic versions.
The proposed new Sentencing Code contains 416 clauses and 28 schedules
The commission said its recommendations will save more than £250 million over 10 years by avoiding unnecessary appeals and reducing delays, as well improving public confidence.
It emphasised the new code will not alter maximum sentences, subject any offender to a harsher penalty than could have been imposed at the time of their offence, reduce judicial discretion or replace sentencing guidelines.
Director of Public Prosecutions Max Hill described the proposed Sentencing Code Bill as a “significant leap forward”, saying it will “enable all who are involved in criminal justice to read the relevant provisions clearly and, for the first time through the clean sweep mechanism, in one place”.
Senior judge Sir Brian Leveson, the head of criminal justice in England and Wales, said: “The need for a clear, logically structured statute governing sentencing procedure is long overdue.
“The commission’s code is welcomed by judges and practitioners for the clarity it provides. It will bring confidence to the public generally that sentences handed down are accurate and lawful. It will, moreover, save vast amounts of time and money.
“The parliamentary time required to enact the code will be negligible. What are we waiting for?”