London houses upwards of 600,000 illegal migrants - Telegraph | 25 Jan 2025 | Upwards of 600,000 illegal migrants are living in London, The Telegraph has reported, citing a new study. This figure represents some 60% of the over one million illegal immigrants believed to be living in the UK. For the entire city, the study, which was obtained by the newspaper under freedom of information laws for the environment, produced a range of 390,355 illegal migrants at the low end of its estimate to 585,533 at the highest, with a median figure of 487,944. Thames Water, a private utility firm, reportedly commissioned the research to assess the number of hidden users of its services to better meet demand.