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How the UK’s new immigration law will put more people at risk of modern slavery

The UK’s illegal migration bill is set to become law after going back and forth between the two houses of parliament. The final sticking point, which the House of Lords tried to address in a series of amendments, was about the bill’s treatment of people who have experienced modern slavery.

The government’s aim with the bill is to crack down on small boat crossings. It stipulates that if someone arrives in the UK irregularly, there will be a duty on the home secretary to detain and remove them from the UK. They will also not be able to access protections under the Modern Slavery Act.

One of the most vocal opponents to this aspect of the bill was Theresa May, former prime minister and home secretary. In one of the final debates, May said that it would “consign more people to slavery”, and allow traffickers to “make money out of human misery”.

The home secretary, Suella Braverman, has said that the government wants to help “genuine” victims of modern slavery. But the new law means that migrants who have been exploited or trafficked to the UK are likely to be deported without receiving the support they are entitled to.

May argues that this will undermine the UK’s efforts to address modern slavery, as those affected by these crimes will be less able to help criminal prosecutions.

Evidence shows she’s right. As our analysis at the Modern Slavery Policy and Evidence Centre points out, prosecution usually relies on testimonies of the victims. If people are not protected, few people will be willing, or in a position to testify in courts. As one survivor put it, if they had been detained and deported under the new bill, “my trafficker would still be walking the streets today”.

Modern slavery protections

Since 2009, protections have been available to anyone identified as a potential victim of human trafficking. These were expanded in 2015 under the Modern Slavery Act to cover those experiencing slavery, servitude and forced or compulsory labour.

If someone is identified as a potential victim, they are referred through the National Referral Mechanism. They are entitled to support including legal advice, accommodation and protection from harm (including deportation) for at least 45 days while their case is assessed.

Ministers have argued that irregular migrants are falsely claiming to be victims of modern slavery to avoid being deported. But these accusations are based on misleading use of statistics.

The immigration minister, Robert Jenrick, claimed earlier this year that 71% of foreign national offenders (non-British citizens convicted of a serious criminal offence) are claiming to be modern slaves. The figure is much lower – around 20%.

The UK statistics authority also warned the Home Office over claims about how many migrants arriving on small boats “game the system” by falsely claiming to be victims.

Our analysis found no published evidence to support these claims. A very small proportion (7%) of people who arrived on small boats between 2018 and 2022 were referred as potential victims of modern slavery. And 85% of them were confirmed by the Home Office as victims – broadly in line with the average for all modern slavery referrals.

Nevertheless, the government insists that removing modern slavery protections for non-UK citizens who enter the UK irregularly will make people in these groups easier to detain and deport, and act as a deterrent for others.

Opposition in the Lords

The House of Lords led opposition to the bill in Westminster, proposing a number of amendments on human rights grounds.

One proposal was to add an exception to the legislation, so that people would not be disqualified from modern slavery protections even if they entered the UK illegally. This was ultimately rejected.

The government did commit to producing new guidance to delay removal of potential victims. However, this is only on condition of their cooperation with the police, and if the modern slavery offence took place in the UK. For a number of reasons, it can take years for victims to come forward to police about their situation.


Read more: Mo Farah was trafficked to the UK – the government's new immigration law could make it harder for modern slavery victims to receive help


Evidence shows that lack of support for victims is a significant factor in low prosecution rates of people smugglers. The Crown Prosecution Service recognises the need to provide support for “vulnerable and/or intimidated” victims.

Immigration policy and modern slavery

The UK’s immigration system is one of complex, costly and restrictive visa regimes, with few legal routes for vulnerable people to come to the UK and be allowed to work. Under the new law, more migrants are likely to be left in precarious situations, at risk of further exploitation.

Seasonal workers in the agricultural sector, for example, say they are treated as “slave labour”. But addressing these issues becomes harder without protections, because there are serious risks to speaking out, including the threat of having your visa revoked and becoming liable for detention and deportation.

And this doesn’t even cover the conditions for those without the right to work, such as those claiming asylum or the safeguarding concerns for migrants who are not permitted to access public funds or basic welfare support.

Close up of Theresa May walking outdoors dressed in a scarf and warm coat
Theresa May was one of the most vocal opponents to the modern slavery provisions in the new law. Will Oliver/EPA-EFE

The government has long described its approach to immigration as “firm but fair”. By dismantling modern slavery protections, while at the same time tightening immigration rules, they are arguably defying their own political balancing act.

The Illegal Migration Act will deny protections to thousands of people, and is based on unevidenced claims about abuse of the modern slavery system. It will almost certainly undermine efforts to address modern slavery.

The protection of those affected by modern slavery should be separated from the politics of immigration controls. This is the only way to ensure people will speak out about exploitation and abuse, without fear of denunciation, detention and deportation.

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