Parliamentary Voting System and Constituencies Bill

The Minister is dealing with the House with his customary courtesy. I quoted a leading academic on the subject of referendums, and he could not think of any previous referendum in any other democratic country that was held concurrently with other polls in some parts of the country, while in other parts of the country there were no other elections. Which example are we following? Which example is the Electoral Commission drawing on in support of the idea of concurrent elections? Can he give a single example from anywhere in the world where a referendum has been held at a time when there are elections in some parts of the country but not in others?