Alistair Darling’s six months as chancellor have been dominated by the Northern Rock crisis. Entering 2008 there is the daunting prospect that the worst is yet to come, should he end up having to nationalise the bank.

With more than £25bn of public money loaned to the bank and billions more committed in guarantees – not to mention thousands of jobs at risk in the bank’s north-east heartland – the political dangers are acute.