Question to the Cabinet Office:

To ask the Minister for the Cabinet Office, how many eligible electors were not registered to vote at UK general elections in (a) 2015 and (b) 2017; and if he will make a statement.

There are no specific estimates of the number of potential electors not registered to vote ahead of the 2015 or 2017 UK general elections. Estimates of the ‘completeness’ of the parliamentary electoral registers (the percentage of eligible people who are registered at their current address) are produced by the Electoral Commision (EC) from time to time, with reference to a published December register. The latest full EC report published in July 2016 relating to the December 2015 register indicated that the register was 85 per cent complete.