PFI is an extremely ingenious idea whereby the private sector bears the capital costs of major projects and in return, taxpayers lease them back for a predetermined number of centuries and thereby only pay 80 or 100 times the original construction cost.

Once in the public domain, cost-effective management of PFI projects is also ensured by out-sourcing the functions to a private company and because of this, essential maintenance, such as changing a light bulb, now costs little more than £700 in most cases.

PFI is thought to stand for Probably F***ing Insane.