One in 12. That is the proportion of London's population that is in the UK illegally, according to a new study. They form 60% of the one million irregular migrants in the country as a whole.¹

Every one of those million has their own story. Some will have come to the UK legally, with a visaAn official document permitting someone to legally enter and stay in a country., but then overstayedSomeone who has stayed longer in a place than they are allowed to. Often a tourist or student visa will allow someone to stay in a country for a number of months or years, but they then must leave or change to a new visa. it. Others entered without formal authorisation, perhaps by forging documents. Another group applied for asylumWhen a state agrees to shelter somebody who is fleeing dangerous circumstances. The right to asylum is protected in international law by the 1951 Refugee Convention., saw their application rejected, but hung on anyway.

Finally, some will be children of other irregular migrants, illegally resident in the only country they have ever known.⁴

The figures come as a blow to politicians of both major parties, who have promised to reduce illegal immigration.

At the end of last year, it was discovered that a large number of illegal migrants, mostly from Brazil, were having to live in caravans because their wages were so low they could not afford to rent their own homes.

Some of the starkest criticisms have been levelled at gig economyA way of working based on temporary jobs or casual part-time work rather than permanent jobs. companies like Uber Eats and Deliveroo. Third parties often create legitimate accounts on their apps under their own names and then rent them out to undocumented workers in exchange for a portion of their earnings, making money out of desperate people.³

Some are even worse off: victims of modern slaveryWhen an individual is exploited by others for personal or commercial gain. They can be tricked, coerced or forced to lose their freedom. Sometimes modern slavery involves human trafficking and often forced labour. who are traffickedWhen people are bought and sold, often to become slaves or forced workers. into the country to do menial work for no pay. It is estimated that more than 130,000 people in the UK are in modern slavery.⁴

What is the solution? Former prime minister Tony BlairTony Blair was the leader of the Labour party. He was British prime minister from 1997 to 2007.  thinks it is digital ID: a unique data profile that you would need to use to access any services at all.

If you were in the UK illegally, either you would have no digital ID, or it would be marked as expired, meaning you would not be able to rent a home, claim healthcare, perhaps even buy things.

Those who found themselves shut out by this system would quickly give up and leave the country, or else could easily be tracked down.

Others are not convinced. They say those without ID would end up falling prey to more exploitative people who would give them illegal access to services and the economy - for a hefty price.

They also fear people with every right to be in the country might end up losing everything because of a computer error.

Should there be compulsory ID cards?

Yes: Britain is one of just six developed countries not to have ID cards. Digital ID would bring the UK not only up to date, but into the future.

No: British voters have rejected the idea of ID cards for decades, so it would hardly be democratic to introduce them. And no solid evidence exists that they would actually be effective in reducing irregular migration.

Or... Illegal migration happens at scale because of unprecedented mobility combined with unprecedented global inequality. Governments that continue to exacerbateMake worse. the latter issue will be unable to deal with the former, by any measure.

Visa - An official document permitting someone to legally enter and stay in a country.

Overstayed - Someone who has stayed longer in a place than they are allowed to. Often a tourist or student visa will allow someone to stay in a country for a number of months or years, but they then must leave or change to a new visa.

Asylum - When a state agrees to shelter somebody who is fleeing dangerous circumstances. The right to asylum is protected in international law by the 1951 Refugee Convention.

Gig economy - A way of working based on temporary jobs or casual part-time work rather than permanent jobs.

Modern slavery - When an individual is exploited by others for personal or commercial gain. They can be tricked, coerced or forced to lose their freedom. Sometimes modern slavery involves human trafficking and often forced labour.

Trafficked - When people are bought and sold, often to become slaves or forced workers.

Tony Blair - Tony Blair was the leader of the Labour party. He was British prime minister from 1997 to 2007. 

Exacerbate - Make worse.