Gordon Brown has put an official seal on the fastest deterioration in the UK’s public finances since the second world war. In eight months, the prime minister has gone from vainglorious boasts about the economy’s resilience to hair-raising warnings of the perils of inaction.

With public sector net borrowing set to increase from 2.6 per cent of gross domestic product last fiscal year to an alarming 8 per cent in 2009-10 and with debt to rise to 57 per cent of GDP, it is clear the boom-bust cycle Mr Brown so presumptuously claimed to have vanquished is back.