Are there more than one million illegal migrants in the UK?published at 12:05 British Summer Time
12:05 BST
Tamara Kovacevic
BBC Verify senior journalist
Image source, EPAImage caption,
Reform UK’s Zia Yusuf (l) spoke at this morning’s news conference alongside party leader Nigel Farage
We’ve been listening to Reform UK leader Nigel Farage’s speech on tackling illegal migration. He spoke for a short while before handing over to Zia Yusuf, the head of the party’s Department of Government Efficiency, to give details about their plan aimed at stopping illegal migration.
Yusuf said: “The total number of illegal immigrants in the country now stands at at least a million.”
The Migration Observatory at the University of Oxford says, external that the term unauthorised migrant – also referred to as “illegal immigrants” – is typically applied to people who enter the country illegally, those who overstay their visa, people who are refused asylum but remain in the country and children born in the UK to “unauthorised” parents. They are not allowed to work or eligible for housing or benefits.
It is very difficult to measure the size of this type of immigration and the government does not have an accurate overall figure.
An estimate by the US think tank Pew Research, external published in 2019 suggested there approximately 800,000 to 1.2 million illegal migrants in the UK in 2017.
However, migration experts noted this number was inflated because it included a large number of people with “indefinite leave to remain” status – meaning they can legally live without restrictions but don’t have a British passport and citizenship.
In response, in March 2025, Pew revised its estimated figures for the UK in 2017 for unauthorised migrants to 700,000 to 900,000., external
This post has been updated to reflect that Pew has revised
its estimate for the number of unauthorised migrants in the UK.