UK’s ‘unsustainable’ debt could reach 320% of GDP in 50 years, OBR warns

The loss of fuel duties as Britain switches to electric cars is likely to blow a hole in the public finances. Photograph: Murdo MacLeod/The Guardian

Britain’s public finances are on an “unsustainable” long-term path with a debt burden that could more than treble without further tax rises to cover the mounting cost of an ageing population and falling fuel duties, the Treasury’s independent forecaster has warned.

The Office for Budget Responsibility said that if economic shocks continue to hit the public finances, debt is on course to reach almost 320% of annual national income (GDP) in 50 years’ time – up from 96% now – unless successive governments raise revenues to offset rising costs.