Question to the Home Office:

To ask His Majesty's Government what is their estimate of the current number of individuals who are in the United Kingdom 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 we do 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 irregular arrivals to the UK as part of the ‘Irregular migration to the UK’ quarterly statistics release on gov.uk. However, this does not indicate the number of irregular migrants currently in the UK.