Fleury-Merogis prison near Paris holds 3,800 inmates
The governor of Europe's largest jail has warned against British government plans to build three so-called Titan prisons each holding 2,500 prisoners.
Joaquim Pueyo told BBC Radio 4's File on 4 programme that he would recommend prisons with a maximum of 600 inmates.
Mr Pueyo heads Fleury-Merogis prison, near Paris, which holds 3,800 people.
However, British Prisons Minister David Hanson said Fleury-Merogis was a success because it had facilities that smaller jails could not offer.
Senior prison officer Bernard Gaudicheau told the File on 4 programme he judged the 40-year-old prison to be a failure.
Mr Pueyo said if large prisons were given the go-ahead in the UK, prisoners should be held in separately-managed buildings holding 400 each with one to a cell.
Mr Hanson said that the Titan prisons would consist of separate blocks.
He added that small jails could not provide the programmes on offer at a prison such as Fleury-Merogis.
But Juliet Lyon, director of the Prison Reform Trust told the BBC: "The French experience of this approach supports what we already know in this country ? the bigger the prison, the harder it is to run, and the less likely it is to cut crime."
Justice Secretary Jack Straw announced plans for more prisons, including three Titan super-jails, in December.
The following month Gordon Brown confirmed the proposals would "go ahead after consultation".
One of the so-called Titan jails, which will be larger than any prison currently used in Britain, will be in service by 2012.
The other two are expected to be built by 2014.
Hear the full story on BBC Radio 4: File On 4 Tuesday 18 March 2008 at 2000 GMT, repeated Sunday 23 March at 1700 GMT or online at the File on 4 website.