I have been asked to reply.
The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.
Letter from Karen Dunnell, dated November 2008:
As National Statistician I have been asked to reply to your question asking what estimate has been made of the proportion of the electorate who have declined to have their details published in the edited version of the electoral register. (236515)
The latest figures for the number of people who registered to vote in the United Kingdom, for local government and European elections, relate to 1 December 2007. At this date the proportion of the electorate who declined to have their details published in the edited version of the register was 39 per cent.