Taxpayers are at risk of spending billions of pounds more on servicing Government debt because of a money-printing spree by the Bank of England, the audit watchdog has warned.

The Bank’s quantitative easing (QE) programme, where newly created money was pumped into the economy by buying Government bonds, led to a surge in the amount of debt with variable interest rates according to the National Audit Office (NAO).

This means that a jump in the Bank Rate has pushed up borrowing costs – potentially costing the Exchequer billions if it is sustained.