The big figures from - but no longer in - Scottish politics are sitting in London watching the coming clash of civilisations in Thursday's by-election to elect a new member of the Labour-controlled UK parliament for Glasgow East.

This is overstated, but only somewhat. Labour's desperate efforts to hold the constituency against the Scottish Nationalists is a clash of different conceptions of British civil society, one which has gone on for nearly half a century. Among those watching in Westminster are Gordon Brown, the prime minister, and his chancellor, Alistair Darling