Britain's national debt has risen above £3tn for the first time, campaigners have claimed. The TaxPayers' Alliance said it believed the public debt had tipped over the landmark in recent days based on the trajectory of spending. The Office for National Statistics (ONS) said Britain's debt stood at £2.99bn at the end of June. In March, the Office for Budget Responsibility (OBR) forecast that the national debt would breach the level in September. £1tn borrowed over just six yearsIt took more than 300 years for Britain's national debt to rise above £1tn, a threshold it crossed in February 2010.