Ex-workers tell of 'chaotic atmosphere' at new £400m prison

The UK's newest prison has had a "chaotic atmosphere" in its first 18 months, former workers have told a BBC investigation.

HMP Millsike, in East Yorkshire, was heralded by the government for setting "the standard for the future" when it opened in March 2025 with 1,500 places.

But former workers have described under-staffing, inadequate training and seeing specialist officers called in to deal with serious incidents on numerous occasions.

Mitie, the company that runs the category C prison, said safety was its "highest priority" and it was "operating in line with plans agreed with the Ministry of Justice".

Millsike was built with a focus on rehabilitation and education and cost about £400m.

It was the first of four new jails due to be opened under a government pledge to create 14,000 places by 2031.

About 1,100 inmates are held there at present, according to the Ministry of Justice (MoJ).

But there have been a number of issues since the prison opened, including:

Reports of a disturbance in November 2025, with a former worker stating a prisoner "lost it" and an elite prison squad had to be called in.

A sewage pumping station breaking down in the same month, amid reports that inmates had flushed clothes down toilets, which Mitie denied.

The conviction of a female prison officer, who was given an eight-month, suspended jail term in June 2026 after admitting to a relationship with an inmate.

The BBC spoke to seven former employees, including a prison officer and staff members.

All but one wanted to remain anonymous, but described a "chaotic atmosphere" inside Millsike.

Six spoke of staffing shortages, and four said they felt unsafe working there.