The Northern Rock crisis could lump more than £10bn (€13.3bn) onto UK public sector net debt in the wake of today’s decision by the Office for National Statistics to include the stricken lender in the government’s accounts as a public financial entity.

The decision, which the ONS stressed follows international guidance and should not be confused with nationalisation, means the Rock’s assets and debts will be counted within public sector finance data, while its billions of pounds of emergency funding from the Bank of England will swell public sector gross debt.