Four in five inmates are living in crowded conditions at Usk prison, new figures show.

Earlier this month Justice Secretary Shabana Mahmood warned without immediate action, prisons would run out of space within weeks – leading to "a total breakdown of law and order".

Plans set out by Ms Mahmood will see thousands of prisoners released earlier than planned as the Government attempts to avert the “collapse” of the prisons system.

Ministry of Justice figures show 221 inmates, or 81.6% of all prisoners at Usk prison were living in crowded cells as of March. This was about the same as the previous year.

Usk prison was one of the most overcrowded across England and Wales.

Nationally, the prison overcrowding rate rose to 23.6% from 22.9% in 2022-23 – a five-year high.

Currently, most prisoners serve 50% of their sentence in jail, with the remainder served on licence, subject to being returned to prison if they violate their parole conditions. The Government plans include a temporary measure to reduce that 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.

Andrew Neilson, director of campaigns at the Howard League for Penal Reform, welcomed the early release scheme, "as it is vital that pressure on overcrowded prisons is reduced as a matter of priority".

He said: "Moving the point of automatic early release will make it easier for services to plan and prepare people before they return to the community.

"The sensible way to protect the public is to ease pressure on a system that has been asked to do too much, with too little, for too long.

"Ultimately, as the prime minister said in a press conference, we "need to be clear about the way in which we use prisons", and we believe this lies in ensuring prioritising reduced prison numbers and ensuring that prisons can be safe and purposeful places for the people who really need to be held in them."

The number of prisoners across the country was also at a record high – 87,129. This included 271 in Usk, which was a slight increase from 265 in 2022-23.

Pia Sinha, chief executive of the Prison Reform Trust said: "After decades of the political arms race to increase sentence lengths; cramming more people into our jails; and failing to provide the necessary places to accommodate them, the prison system has finally run out of road.

"Doing nothing is no longer an option. The government has thankfully recognised the importance of reducing overcrowding as an immediate first step; this will buy some breathing space.

However, Ms Sinha warned with the prison population projected to rise further, longer-term solutions must soon be found.

The Ministry of Justice estimates the increase will be between 94,600 and 114,800 by March 2028.

It is already building six new prisons to create an extra 20,000 places as demand grows for cell spaces.

About 6,000 spaces have been created already and about 10,000 will be built by the end of 2025.