The government has long been accused of finessing the public finances by favouring private finance initiative deals for capital investment projects, such as schools and hospitals, because the debt did not show up on the government's books.

Now, after pondering the problem for five years, the Office for National Statistics has put a £4.95bn figure on the value of the debt of PFI and public-private partnership deals, which it has added to public sector net debt. Its estimate represents what it thinks the government would have to borrow today to buy back a PFI asset for the remainder of its PFI contract.