The decision to return Blakenhurst prison to the public sector after eight years under private management will result in worse conditions for prisoners despite promises from the Prison Service to improve the quality of life for inmates.

Prisoners will be able to spend less time in the fresh air, will be locked up for longer and lose opportunities for evening visits.

Shadow home secretary Ann Widdecombe criticised a "politically motivated decision" but the Prison Service said its bid had been cheaper and offered higher quality than that by a competing private sector company.