EU citizens who missed the June 30 deadline are set to lose the right to work and receive benefits. Activists and lawyers fear that uncertainty over new immigration rules will enable criminals to tighten their grip over trafficking victims.
Luke Piper, head of policy at the3million, a campaign group for EU citizens in Britain, said: "Those who perpetuate ... slavery and trafficking take advantage of things like this [deadline]. I think it will be devastating for vulnerable people.
"Criminals could tell people ‘you missed the deadline, you're in trouble, the police will deport you, stay with us – we'll protect you'."
More than 5.6 million EU citizens have applied for residency rights in Britain so far, but many people, including victims of trafficking, were unaware of the deadline and face language barriers or lack access to legal advice, according to advocates.
Carita Thomas, an immigration lawyer for ATLEU – a charity providing legal representation to trafficking survivors – said the deadline had created a "cliff-edge", with traffickers seeking to mislead or instil fear in people who missed it.
"Traffickers are very clever and clued up on how the immigration system works," said Ms Thomas, who has urged the government to scrap the deadline. "They can use any deadline as a coercive measure."
Britain's interior ministry said it would accept late residency claims where there was a reasonable excuse.
"We have a well-established process for prioritising cases of vulnerable applicants, including victims of modern slavery," a spokeswoman said in a statement.
Yet activists said victims of trafficking and slavery would not know they could apply after the deadline and that it was unclear at what point late claims would no longer be considered.
Eliza Stachowska, of campaign group Hope for Justice, said the issue was complicated by the fact that victims often lacked documentation to show how long they had been in Britain and the Covid-19 pandemic had hampered access to immigration advice.
About 10,613 potential victims were referred to the interior ministry for support last year.