EPEC Guide to Guidance [#83, pages 31-33] describes the range of financing agreements for a typical PPP. These financing agreements are often not finalized until after the contract has been awarded. In most cases, interested lenders are identified at the proposal stage. However, before those lenders will commit to provide finance, they often carry out detailed due diligence on the project and PPP agreements (as described in Farquharson et al [#95, pages 124-125] There are risks associated with this process-lenders may require changes in the PPP agreements before agreeing to finance the project, or financing terms may change from what was assumed in the proposal. One way to mitigate these risks can be to ask for 'firm' financing commitments at the proposal stage-but this can be difficult and expensive to procure, and risk reducing competition.
Section 1.4: How PPPs Are Financed provides more information on the risks associated with PPP financing and reaching financial close.