Leave campaigners have threatened a legal challenge over the extension of the voter registration deadline, with potentially tens of thousands of extra remain voters signing up after the first deadline. Professor Philip Cowley is cited in the article after highlighting that between 1 January 2015 and the final day for registration for the 2015 General Election, just under five million people applied to register to vote in England and Wales. The register subsequently grew by 1.35 million. Most of these were already registered, perhaps doing so on a "just in case" basis, or they were not eligible to vote. The system does not allow anyone to check whether they are already on the register.More ยปAlso featured in the Financial Times