Privately-run prisons perform worse than those run by the public sector, a document leaked to the BBC suggests.
The jail population exceeded 81,000 last year
The Prison Service papers include an internal "league table", which ranks all jails in England and Wales.
It shows that most privately-managed prisons score badly on security and maintaining order and control.
Prison governors want the government to re-think private management of prisons. But the Prison Service says private and public sector jails cannot be compared.
BBC home affairs correspondent Danny Shaw said the report would re-open the debate about private sector involvement in prisons, at a time when private companies were bidding to fund and operate a series of new jails.
A national table, ranking performance in six categories, showed that 10 of the 11 privately-run prisons in England and Wales were in the bottom quarter.
Peterborough Prison, managed by a private firm for three years, came last out of 132 prisons and prison clusters, with low marks for reducing re-offending, organisational effectiveness and decency.
The Prison Governors Association has called on the government to re-think its policy of involving private firms in the management of prisons.
But sources within the private security industry said the findings shown in the documents were based on subjective assessments.
The Prison Service said direct comparisons between the private and public sectors were "not appropriate" because some figures were counted differently.
Privately-managed prisons, which were introduced to the UK in the 1990s, are assessed by HM Inspectorate of Prisons in the same way as public sector prisons.
There are currently 11 prisons contractually managed by private companies.
In December, the government announced the building of three new "super-prisons", each housing about 2,500 offenders.