Question to the Home Office:

To ask the Secretary of State for the Home Department, what recent estimate her Department has made of how many people are living in the UK illegally.

By its very nature, it is not possible to know the exact size of the illegal population, or the number of people who arrive illegally, and so the Home Office does not seek to make any official estimates of the illegal population. In June 2019, the Office for National Statistics (ONS) published a note on ‘measuring illegal migration’.

The Home Office does publish statistics on detected irregular arrivals to the UK as part of the ‘Irregular migration to the UK’ quarterly statistics release. However, this does not indicate the number of irregular migrants currently in the UK.