He had proposed that there should be an intermediate court comprising a judge and two magistrates for mid-range offences.
The reforms, expected to be outlined next week, put Lammy on a collision course with the legal profession.
Suella Braverman, a former Home Secretary and Attorney-General, said: “This is a serious assault on our liberty. Trial by your peers is a fundamental right in our democracy, and goes to the core of who we are as a nation.”
Riel Karmy-Jones KC, the chairman of the Criminal Bar Association (CBA), said removing jury trials would undermine “a fundamental feature of the British constitution, and the British justice system, for over 800 years”.
She added: “The erosion of the right to jury trial will break the increasingly thin connection between the state and ordinary people, and risks undermining social cohesion and trust in the criminal justice system. Once that trust disappears, fears of tyrannical governments increase and the faith in justice evaporates for good.”
Lammy has previously been a strong defender of the jury system, declaring when it was under threat during the Covid pandemic that “jury trials are a fundamental part of our democratic settlement”.
He added: “The Government need to pull their finger out and acquire empty buildings across the country to make sure these [trials] can happen in a way that is safe… you don’t fix the backlog with trials that are widely perceived as unfair.”
The “once in a generation” changes to the jury system have been drawn up in an effort to tackle the record backlogs of court cases, now standing at nearly 80,000 in Crown courts.
It means that some cases are now being scheduled for 2029, with defendants increasingly “playing the system” by pleading not guilty and choosing a jury trial in order to boost the chances of proceedings collapsing.
Lammy wrote to ministers to say that there was “no right” to jury trials in the UK, and that drastic action was needed to cut the backlog of cases in Crown courts in England and Wales.
It is anticipated that as many as 75% of trials will be heard by a judge sitting alone instead of a jury under his proposals, contained in a briefing document headed “sensitive and official”.
It is understood that the Justice Secretary has retained Leveson’s proposal that lone judges should hear complex fraud, financial and cyber crime cases to end the need for juries to give up a year or more of their lives.
It is believed the trial to hear prospective prosecutions arising from the 2017 Grenfell Tower fire could be one of the first complex trials to be heard by a judge sitting alone.
‘No final decision taken by Government’
Last week, Sarah Sackman, the justice minister, defended the need for radical reform, citing the fact that victims of severe sexual assault are now being routinely told it could take four years for their cases to reach court.
“Behind these 80,000 odd cases that are waiting in the backlog, there are individual stories and individual lives being put on hold,” she said.
“No one is being served in the case that we saw. Not the accused, who’s currently being remanded in jail, not the victim who’s been waiting since she first reported her crime years ago.
“I’ve spoken to victims and survivors who tell me they’ve lost their jobs, they suffered mental breakdown all the while that they were waiting. More victims and witnesses are pulling out of the process because they cannot wait that long. That is a compelling illustration of justice delayed being justice denied.”
A Ministry of Justice spokesman said: “No final decision has been taken by Government. We have been clear there is a crisis in the courts, causing pain and anguish to victims, with 78,000 cases in the backlog and rising, which will require bold action to put right.”
Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.