Emergency plans to avoid prison overcrowding have been activated in the North of England as more rioters are sentenced.

Operation Early Dawn, a long-standing plan which allows defendants to be held in police cells and not summoned to magistrates’ court until a space in prison is available, was activated on Monday morning, the Ministry of Justice said.

The measure will be put in place in the North East and Yorkshire; Cumbria and Lancashire; and Manchester, Merseyside and Cheshire regions.

Prisons and probation minister 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.

“However, thanks to the hard work of our dedicated staff and partners, we have brought forward additional prison places and now introduced Operation Early Dawn to manage the pressure felt in some parts of the country.”

National Police Chiefs’ Council custody lead Deputy Chief Constable Nev Kemp said: “We are working closely with criminal justice system partners to manage demand in the system and ensure that the public are safe.

“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.”

After the riots that broke out across England following the stabbing of three girls in Southport, a total of 460 people had appeared in magistrates’ courts in relation to the disorder by the end of Thursday.

More than 460 people have appeared in magistrates’ courts across England in connection with the disorder that followed the stabbing of three girls in Southport (PA)

Operation Early Dawn was previously triggered by the Conservative government in May in a bid to tackle overcrowding in jails.

Last month, the Ministry of Justice said violence and self-harm in prison had risen to “unacceptable” levels as overcrowding pushed jails to the “point of collapse”.

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 – which does not apply to those convicted of sex offences, terrorism, domestic abuse or some violent offences – is expected to result in 5,500 offenders being released in September and October.