The Treasury issued guidance on standardising PFI contracts last week in a move widely seen as an attempt to appease union critics of the scheme.

'The guidance will end once and for all the argument that PFI is about mortgaging the future, ' chief secretary to the Treasury Alan Milburn said. 'In future, where it is appropriate, ownership of assets built through the PFI will revert to the public sector at the end of the PFI contract.'

His announcement follows a similar move in Scotland last month.

The move was welcomed by Unison, but criticised by supporters of PFI, who argued it would be more difficult to interest the private sector in schemes. The Treasury guidance has now emerged ahead of the Department of Health's much-delayed 'handbook' of 'how to do' PFI projects. NHS finance director Colin Reeves told HSJ th is week that it was 'imminently imminent'.