STAFF at a private prison where about 50 inmates took over a wing predicted there would be trouble when the workforce was cut, a union official has said.

The disorder at HMP Northumberland, in Morpeth, on Friday night, lasted for about seven hours and required the assistance of specially-trained colleagues from other prisons around the North-East to bring it to an end.

Terry Fullerton, who represents the region on the Prison Officers Association national executive committee, said members had raised concerns about staffing levels as far back as December.

He said since then around 130 staff had left, leaving fewer than 200 uniformed staff to guard 1,350 inmates.

Mr Fullerton said: "Staff were concerned that the reduction would lead to what happened on Friday night.

"It doesn't take inmates long to realise that staffing levels have reduced and that there are less of the 'white shirts' that are needed to keep control."

Inmates refused to return to their cells and warned staff to leave the area, which they did, allowing them to take over until a specialist squad of officers was assembled.

Sodexo Justice Services, a private firm which manages HMP Northumberland, said an investigation was being held into what happened.

HMP Northumberland, a category C prison, was formed from a merger of the former Acklington and Castington jails.