A narrow vote in favour of joining might not be taken as final. In the current configuration of British politics, a bare majority may not be enough. Having come close to prevailing, the Tories might choose to keep the question alive. Britain could end up in the worst of all worlds - still deeply undecided about the sort of country it wants to be and unable to act effectively to shape the Europe that is developing around it. Britain will remain stuck on the mar gins of Europe so long as its politics are polarised as they are today.
Electoral reform is a prerequisite of any durable settlement on the European issue.
But the necessary fundamental political realignment does not require proportional representation. It can be achieved by a much more modest change. The system recommended by Lord Jenkins's independent commission on the voting system was a hybrid of the Australian alternative vote with European-style PR so contrived and opaque in its workings that it would probably be rejected by voters in a referendum. Moreover, because it involves two tiers of MPs, thereby weakening the link with constituencies, it is unlikely to be acceptable to a majority in the Commons. As a result, PR is dead in the water for the foreseeable future.