The government has activated emergency measures to ease prison overcrowding as more rioters are being sentenced for their role in recent unrest.
Across the north of England and parts of the midlands, defendants waiting for a court appearance will be kept in police cells until prison space is available.
The system, known as Operation Early Dawn, was activated on Monday morning. It was previously used by the Conservative government in May.
Prisons Minister Lord Timpson has said the emergency measures will help "manage the pressure felt in some parts of the country".
But the vice president of the Prison Governors' Association, Mark Icke, said he was "not sure" how much the measures will help as the prison system has been "lurching from crisis to crisis for some time".
Operation Early Dawn was first implemented on Monday to cover the north of England, and later expanded to include the East and West Midlands.
The regions affected by the move are:
- North East and Yorkshire
- Cumbria and Lancashire
- Manchester, Merseyside and Cheshire
- East and West Midlands
The government said its action to "tackle violent thuggery on our streets" has "exacerbated long-standing capacity issues in our prisons".
Prime Minister Sir Keir Starmer blamed the emergency measures on "a basic failure" of his predecessor Rishi Sunak's government.
"[These decisions are] having to be taken for one reason and one reason only, and that is the terrible inheritance on prisons that we had as an incoming government from the previous government," he said.
More than 1,000 people have been arrested in connection with violent disorder following riots in England and Northern Ireland earlier this month, according to the National Police Chiefs' Council (NPCC).
The riots erupted following the spread of misinformation online after three girls were killed in Southport.
The Crown Prosecution Service says more than 470 people have been charged with offences so far.
On Friday, two men received the longest sentences yet related to the disorder. David Wilkinson, 48, was jailed for six years for offences including racially/religiously aggravated criminal damage and attempted arson.
John Honey, 25, was sentenced to four years and eight months for offences including racially aggravated criminal damage.
BBC analysis of prison figures has revealed how difficult it was going to be for jails to cope with a sudden influx of both remand and newly-sentenced prisoners.
Four days before the riots, HMP Durham - the nearest “reception” prison to the disorder in Sunderland, which would therefore normally be a likely first institution to accommodate newly convicted local men - had just one spare bed because it was already holding 984 inmates.
Under Operation Early Dawn, defendants will only be summoned to a magistrates' court when a space in prison is ready for them.
This means court cases could be delayed, with people kept in police cells or released on bail while they await trial.
The Ministry of Justice said that anyone who "poses a risk to the public" will not be bailed and the police's ability to arrest criminals will not be affected.
Deputy Chief Constable Nev Kemp of the NPCC said: "Policing will continue to arrest anyone that they need to in order to keep the public safe, including policing protests and events and ensuring that people are arrested as expected."
Lord Timpson said: "We inherited a justice system in crisis and exposed to shocks. As a result, we have been forced into making difficult but necessary decisions to keep it operating."
Prison Officers' Association chair Mark Fairhurst told BBC Breakfast that people who are handed custodial sentences might end up being sent to a prison elsewhere in England and Wales.
He said: "We will make sure that those people who need to be in prison, will be in prison.
"Not necessarily in the area where they live - they may be two, three hundred miles away from home - but we will guarantee people a prison cell."
The current capacity of the prison system in England and Wales is 89,191 prisoners. As of Friday, the prison population was 87,893.
Tom Franklin, chief executive of the Magistrates Association, told BBC Radio 4's Today programme it was "no surprise" that the emergency measures had been activated.
He said the justice system had been in crisis "for years now, and often unseen by the public".
He added that the civil disorder in recent weeks has brought the importance of a "well-run, well-funded justice system" into the public consciousness, and sparked discussion about "what needs to be done to fix this for the longer term."
More prison spaces could be created in September, when separate measures to release some inmates early come into effect.
In July, Justice Secretary Shabana Mahmood announced plans to cut the proportion of the sentence inmates must serve behind bars from 50% to 40%.
The temporary move is expected to result in 5,500 offenders being released in September and October. It does not apply to those convicted of sex offences, terrorism, domestic abuse or some violent offences.
Mr Franklin told the BBC that the "enormous pressure" on prisons will "ease" after this plan comes into effect.
Asked if that measure should be brought forward, he said there are "all sorts of steps that need to be taken to bring that about".
He added that the probation service is "working flat out" to implement the plan on 10 September, so it would not be realistic to bring it into effect any sooner.
Last week, the government confirmed those involved in recent unrest would not be excluded from its plans to release some inmates from jail early.
Government sources have stressed that Operation Early Dawn is an emergency measure, which will only operate in the short-term.
Yet as it stands there is no fixed end date for the scheme, which will be kept under constant review.
When it was last activated in May, the Conservative government said the measure would stay in place for a week.
Additional reporting by Alex Boyd
Policing
Criminal justice system
Prisons