Rapidly rising pension and healthcare spending will reduce the debt status of the world's richest industrialised countries to junk within 30 years unless their governments move quickly to balance budgets and reduce outgoings, a report published on Monday warns.

Standard & Poor's, the credit ratings agency, says if fiscal trends prevail, the cost of ageing populations will fuel downgrades of France, the US, Germany and the UK from investment grade to speculative, or junk, category France by the early 2020s, the US and Germany before 2030 and the UK before 2035. They are currently in the top Triple A category, ensuring they can borrow at low rates.