An extraordinary crisis on global markets provided an extraordinary moment in British politics. Gordon Brown’s government is taking a £50bn stake in the banks. The Conservatives, heirs to Margaret Thatcher and guardians of the free-market flame, have given their blessing.

The surreal scenes in the Commons – David Cameron and Nick Clegg assuring Mr Brown of the support of the Tories and Liberal Democrats alike – spoke to the way the crisis has transformed the dynamics of domestic politics.