Question to the Home Office:

To ask the Secretary of State for the Home Department, whether her Department has made a recent estimate of the number of people in the UK who have dual citizenship.

The data requested is not available from published statistics. Immigration statistics for the last 10 years are published at Migration statistics. While these include statistics for naturalisation/registration as a British Citizen, they do not include those who are deemed automatically a British Citizen without the need to apply.