There are around 1.3m prosecutions in England and Wales every year, and 10% of those cases go before a Crown Court. Of those, three out of 10 result in trials.

The reforms appear to mean that more than two out of 10 will still go before a jury. Critics of restrictions to trial by jury – including almost all barristers – say it won’t have any impact on the backlogs because the real problem has been cuts to the Ministry of Justice.

Shadow justice secretary Robert Jenrick accused Lammy of “scrapping the institution he once lauded”.

Lammy has previously said that cutting juries would be a mistake, but told the BBC ahead of the announcement that the “facts had changed” and the government needed to bring in reforms to clear the backlog.

Jenrick told 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?”

Lammy, in response, said the changes were needed because the previous government had cut court sitting days and magistrates already deal with the vast majority of UK trials.

Abigail Ashford, a solicitor advocate with Stokoe Partnership, who represents clients in the Crown court, said the reforms risked trust in justice.

“Judge-only trials risk deepening existing inequalities and eroding confidence among communities who already feel marginalised,” she said.

“In complex or sensitive cases, removing the community from assessing credibility and fairness undermines trust in a way that cannot be compensated for by concentrating decisions in the hands of a single judge.”