3.19 Financial structures, variously known as "underpinned debt" and "de-risked PFI", have been discussed and used in the market. These structures are based on the concept that risk is greatest during the construction period and that, during the operational phase, the authority could benefit from lower risk premia on the debt if it were to guarantee a portion of the debt or underpin a certain level of compensation to lenders on termination for contractor default. The Treasury intends to issue guidance on this type of financing structure.