You asked
I would like to know how many UK dual citizens there are currently living in London or failing that for the most recent year that data is available.
We said
Thank you for your Freedom of Information request asking how many UK dual citizens there are currently living in London or failing that for the most recent year that data is available.
The best data we hold for UK dual citizens is from the 2011 Census, although there wasn't a specific question asked on dual citizenship. We have published the spreadsheet accompanying this response named 'CT0061 - National identity (detailed) London to LSOA' and 'CT1139 - Bespoke passport held (single and dual passports held) by ethnic group (London Row 1784 to 2080)'.
The Passport Service, part of the Home Office, may have more information to help with your request.
Please do not hesitate to contact us directly on pop.info@ons.gov.uk if you require anything further.