Question to the Ministry of Justice:

To ask Her Majesty's Government, further to the reply by Lord Keen of Elie on 8 February, what the “certified capacity of the prison population” refers to; and whether the prison population has exceeded the Certified Normal Accommodation of the prison system at any time over the last 20 years.

Prison capacity is defined using the terms Certified Normal Accommodation (CNA) and Operational Capacity. These terms are defined separately as:

• CNA, or uncrowded capacity, is the Prison Service’s own measure of accommodation. CNA represents the good, decent standard of accommodation that Her Majesty’s Prison and Probation Service aspires to provide all prisoners; and

• the Operational Capacity of a prison is the total number of prisoners that an establishment can hold taking into account control, security and the proper operation of the planned regime. It is determined by Prison Group Directors on the basis of operational judgement and experience.

The total prison population is in excess of CNA however this total is always below the total operational capacity of the estate.