Government backing given to troubled lender Northern Rock has pushed national net debt to 43.1 per cent of gross domestic product, Office for National Statistics (ONS) figures show.

In March, national debt stood at 37.1 per cent when costs associated with the Northern Rock bailout were excluded.

The government’s ceiling for public debt stands at 40 per cent, as set out by the Treasury’s sustainable investment rules, the BBC reports.

Chancellor of the exchequer Alistair Darling has responded by stating that the impact on public debt will be temporary and is the result of exceptional circumstances.

"This year is likely to be a tough one for public finances," said David Page, an economist at Investec.

Levels of individual debt have also risen sharply in recent months, with the Ministry of Justice identifying Yorkshire as the region with the highest level of bankruptcy and individual voluntary arrangement (IVA) applications during the first quarter of 2008.