Government Departments use the Treasury's value for money guidance in making assessments about the suitability of PFI as opposed to conventionally financed programmes, both at a project and programme level. This is available at:
http://www.hm-treasury.gov.uk/documents/public_private_partnerships/additional_guidance/ppp_vfm_index.cfm
The Government constantly monitor risks and liabilities relating to PFI but do not undertake a central assessment of liabilities in the event that all PFI/PPP schemes fail, not least because any such figure would be dependent on a number of variables surrounding the specific circumstances of the termination.
The Project Review Group, which oversees the approval process for local authority PFI projects that receive Government support via PFI credits, has an established evaluation framework. This framework covers the criteria on which projects seeking approval will be assessed. Additionally, Departments are required to use the PFI value for money assessment guidance issued by HM Treasury. These documents are available through the Treasury PPP website at:
http://www.hm-treasury.gov.uk/documents/public_private_partnerships/ppp_projectreview_group.cfm
http://www.hm-treasury.gov.uk/documents/public_private_partnerships/additional_guidance/ppp_vfm_index.cfm
Beyond this, Departments determine their own priorities reflecting public service agreements and wider Government objectives in deciding which projects are put forward for PFI credits.