An independent monitoring board has criticised the justice secretary's decision to close Blundeston Prison.
The board, which publishes an annual report on the Lowestoft jail, has called the plans "ill-conceived, premature and rushed".
In an open letter, seen by ITV News Anglia, it said HMP Blundeston had consistently been praised for the excellent relationships between staff and prisoners.
The prison is due to close by the end of the year as part of a government plan to bring in new "super prisons".
But the IMB questioned whether those relationships would be as strong:
"Prisoners who appreciate the support they get at the prison are unhappy at the closure which de-stabilises their rehabilitation, moves them to another prison and means, in some ways, they will have to start all over again."
More top news
Armed police patrol the region's biggest Christmas market in response to the heightened nation terror threat.
Sister Laura and Philippa from Bury St Edmunds have beaten the odds by giving birth to their babies on the same day
A man student from Luton who told an undercover police officer he was willing to use a suicide vest has been detained for six years.