UK debt could hit 300% of GDP, OBR warns triple lock fuels unsustainable rise

The Office for Budget Responsibility (OBR) warned that the United Kingdom’s public debt, currently around 95% of GDP (just under £3 trillion), could climb to 300% of GDP by 2075. The surge would be driven primarily by state‑pension spending, which the OBR projects to rise from 5% to about 9% of GDP over the next 50 years, with the triple‑lock guarantee – raising pensions by the highest of earnings, inflation or 2.5% – accounting for roughly a third of that increase. Health spending is also expected to rise from 8% to 13% of GDP, adding further pressure.

The OBR described the trajectory as “unsustainable and ever‑rising”, urging early action such as reforming the triple lock, which could cut pension outlays by up to 5% of GDP if replaced with inflation‑only uprating. It also flagged the need for an additional £28 billion a year in defence spending and highlighted the impact of an ageing population on health and social‑care costs.

Incoming Prime Minister Andy Burnham has pledged to retain the triple lock despite growing calls for its removal, while critics argue the policy is financially untenable. The OBR noted that delaying a further increase in the state‑pension age could cost taxpayers an additional £6 billion in today’s terms.