Leaked plans last week revealed the Deputy Prime Minister wanted to go even further, with juries only hearing murder, rape, manslaughter and “public interest cases” carrying sentences of five years and over.

This prompted widespread fury from lawyers, judges and rival political parties.

Under Mr Lammy’s new plans, some sexual assault, burglary, drug dealing and robbery cases will now be heard by a single judge.

Ministry of Justice modelling suggests that the number of cases going to a jury trial will be cut in half.

But the plan sparked fresh fury, with Shadow Justice Secretary Robert Jenrick declaring: “Last year, the entire budget for courts and legal aid was £5.5 billion.

“Almost exactly the same money – 5.4 billion pounds – that we spend on illegal migrants.

“He defends their rights under the ECHR, but not our rights under Magna Carta.

“And for what? He can’t even guarantee that in 4 years tim this will reduce the court backlog.

“With this Justice Secretary it’s just delayed and justice denied.”

And the top Tory revealed both the Prime Minister – the former Director of Public Prosecutions – and the Justice Secretary previously opposed reforms to jury trials.

Mr Jenrick also goaded Mr Lammy for finally respoding to a major justice crisis in Parliament.

He told MPs: “When 12 prisoners were mistakenly released after the introduction of his brilliant, new checks, he didn’t bother to come to Parliament to inform the country.

“Then when I asked why his Department is paying out compensation to terrorists in prison, he didn’t show up.

“And when the news of his plans to scrap jury trials mysteriously emerged in the press last week, he was nowhere to be seen.

“Much like the prisoners on his watch, he’s been a man on the run.

“The Lammy Dodger of this sorry charade for a government.”

Outlining his plans, Mr Lammy told Parliament: “I will create new ‘Swift Courts’ within the Crown Court, with a judge alone deciding verdicts in triable-either-way cases with a likely sentence of three years or less. Sir Brian estimates that they will deliver justice at least 20 percent faster than jury trials.

“Sir Brian also proposes restricting defendants’ right to elect for jury trials.

“Our world-leading judges should hear the most serious cases.

“And I agree that they – and the magistracy – should decide where a case is heard. This will prevent defendants from gaming the system: Choosing whichever court they think gives the best chance of success… …and drawing out the process, hoping victims give up.”

Despite Mr Lammy’s radical reforms, which critics have warned could fail victims, or lead to miscarriages of justice, the Crown Court backlogs could continue to get worse.

Ministry of Justice figures show a record-high backlog of crown court cases totalling more than 78,000, and trials listed as far as 2030.

Ministers have warned the backlog could rise to 100,000 by 2028 if nothing is done, with a growing number of victims giving up on seeking justice because of the lengthy delays.

Mr Lammy told MPs: “The backlog will get worse before it gets better.

“But we are pulling every possible lever to move it in a positive direction and my ambition is for the backlog to start coming down bythe end of this Parliament.”

And the under-fire Justice Secretary insisted jury trials will remain a “cornerstone” of the UK legal system, whilst magistrates will have their sentencing powers extended.

They will be able to lock criminals up for 18 months, though Mr Lammy admitted he could extend this to two years.

He said: “Alongside these changes, we will increase magistrates’ court sentencing powers to 18 months so that they can take on a greater proportion of lower-level offending and relieve pressure on the Crown Court. I will also take a power to extend that to 2 years.

“These reforms are bold. But they are necessary. I am clear that jury trials will continue to be the cornerstone of the system for the most serious crimes… …those likely to receive a sentence over three years… …and all indictable-only offences. Among others, this will include: Rape, murder, manslaughter… …grievous bodily harm, robbery, and arson with intent to kill.”

The Ministry of Justice will scrap the right of defendants to “elect” a jury trial for so-called “either way offences”.

This, they believe, will end the “emergency” engulfing the Crown Court system with trials listed for 2029 or 2030.

Judges will initially assess a case, and if it is “likely” to result in a three-year prison sentence or less, it will be heard by either a magistrate or the new Crown Court Bench Division.

Neither of these will require a jury, it is understood.

But judges in the Crown Court Bench Division will retain full sentencing powers, meaning that if the evidence of a case stipulates that a longer prison term is necessary, the judge can utilise them and lock up the criminal for longer.

This means that, whilst hearing a sexual assault case, a single judge could hear all the evidence, convict and sentence a criminal to four or five years behind bars.

Justice chiefs believe it will still take years for the Crown Courts backlog to fall. The policy to abolish jury trials will be deemed a success if the backlog begins to fall by the end of this Parliament – in 2029, it is understood. The Bar Council has urged him not to replace juries with single judges, warning that doing so could damage public trust.

Mr Jenrick hit back, telling the Commons: “Why on earth does this Justice Secretary think he has a mandate to rip up centuries of jury trials without even a mention of it in his party’s manifesto?

“In his twisted logic, he says he’s scrapping juries to save them, but be in no doubt, if the Justice Secretary gets away with this, it is the beginning of the end of jury trials.”

Mr Jenrick added that it had been 800 years since the Magna Carta and we have “another unpopular leader who doesn’t listen to his subjects”.

He said: “Our ancestors did not stop bad King John only to be undone 800 years later by this Prime Minister and his court jester.”

Mr Lammy responded that the changes were needed because the previous Tory government had cut court sitting days and magistrates already deal with the vast majority of UK trials.

He said: “He knows too that the Conservatives took the juries away from defamation cases in 2013. Back in 1933, we had juries sitting in civil cases.

“So, of course, we reform to meet the needs of the system.”