HC Deb 23 June 2004 vol 422 c1418W
Mr. Simmonds

To ask the Secretary of State for the Home Department what estimate his Department has made of the number of illegal immigrants in Lincolnshire. [179434]

Mr. Browne

Official estimates of the number of illegal immigrants in the United Kingdom do not exist. The Government have commissioned research into the methods used in other countries to estimate the size of their illegal populations in order to define methods appropriate for the UK.

The work required is challenging because, by definition, illegal migrants fall outside of official statistics and are therefore difficult to measure. People illegally present in the UK are also motivated to ensure they remain hidden, which is a challenge to conducting research.