IPPR researcher Tim Gosling said that in the health service, PFI documents were always placed in the public domain, as it was a legal requirement, but obtaining comparable information in other fields was more difficult.
He said: "Outside the NHS it is much harder to obtain PFI documentation, particularly after deals have been signed." Gosling added that the government should make regulations governing the NHS binding elsewhere.
Hamish Henderson-Begg, the head of PFI at consultant Babcock International, said: "Provided that there are safeguards for some sensitive information, we are happy for almost all PFI information to be made public."
The IPPR survey disclosed that whereas most documents that it requested from the NHS were made available, councils released only half of those requested.
Central government refused to make any PFI documents available for the survey.