Gordon Brown may be days from departure. Or – like the twitching body at the end of a hangman’s noose – his final spasms may be more drawn out. But there is an altogether more dramatic subplot being played out as the New Labour government reaches its last act. For the death throes of this government herald the end of something remarkable in British politics – the era of radicalism.

The immediate causes of Mr Brown’s demise may be mundane matters: the limitations of his personality and the cost of Jacqui Smith’s bath plug. He is also being subsumed by an economic tide.