What is bringing this to a head, of course, is the decision of our Brussels colleagues, as they desperately struggle to save the doomed euro, to go all out for a new treaty, designed to take them a huge further step towards “full political and fiscal union”. If, as expected, they agree this at December’s European Council, the treaty will take at least a year to negotiate, followed by a long and contentious ratification process, which would take us beyond Britain’s next general election.