Robert Jenrick will vow to abolish the Sentencing Council when he addresses the Conservative Party conference on Tuesday.
The shadow justice secretary is expected to set out plans to put ministers in charge of sentencing policy, arguing that the current situation has resulted in a “two-tier nightmare” with people treated differently by the courts.
He will say: “The Sentencing Council is not fit for purpose.
“Never again can the British people face the prospect of two-tier justice.”
The council, responsible for setting guidelines on sentencing, found itself at the centre of a row earlier this year after it issued guidance recommending judges take into account factors such as ethnicity or gender when deciding whether to ask for a pre-sentence report.
Mr Jenrick and others said the guidance would result in people facing a lesser punishment on the basis of their ethnicity.
The proposal was withdrawn and the Government has introduced legislation to require any new guidance to be approved by ministers.
In his speech on Tuesday, Mr Jenrick is expected to say: “We are slipping into a two-tier nightmare under Keir Starmer.
“All too frequently the law is not applied equally.
“No more. Every single person in this country must be treated exactly the same, regardless of their background.”
Academic evidence suggests there is some disparity in sentencing, with offenders from ethnic minorities more likely than white offenders to be imprisoned for certain offences, even when controlling for legal factors such as guilty pleas or previous convictions.
Mr Jenrick will also accuse the Sentencing Council of “watering down” sentences by recommending ranges of jail terms that do not go up to the maximum allowed by Parliament.
A Labour Party spokesperson accused the Conservatives of “yet more rank hypocrisy”, adding: “The Conservatives backed the proposed changes to pre-sentencing reports when they were announced and did nothing to stop them when they were in government.
“Labour took action the moment we uncovered their mistake.
“This is just another cynical gimmick from Jenrick, a man who constantly undermines the independence of the judiciary just to further his own career.”
Mr Jenrick signalled he would take aim at Attorney General Lord Richard Hermer KC in his speech.
“I’m going to talk about my particular bete noire, the attorney general,” he said on Monday during a fringe event.
Mr Jenrick’s speech comes on the third day of a conference in which the party has been determined to demonstrate unity despite its polling difficulties and questions about Kemi Badenoch’s leadership.
The former leadership contender, who has recently taken up boxing, has been insistent that he is backing Mrs Badenoch.
Asked during a fringe event on Monday whether he would stand for the party leadership should there be a vacancy, he said: “There isn’t a vacancy and I don’t expect there will be.
“My expectation is that Kemi will lead this party into the next general election.”
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