Theresa May’s determination to continue counting foreign students in the government’s immigration target left her increasingly isolated on Thursday night, after official figures revealed that fewer than 5,000 a year stay on after their visa expires.

A string of Conservative and opposition politicians called on the prime minister to end the focus on overseas students as it appeared the government had been drastically overestimating the risk that they remain in Britain illegally.

New data, published by the Office for National Statistics and based on recently created exit checks at Britain’s borders, showed just 4,600 overstayed their visa last year. Estimates for previous years had been close to 100,000.

The Liberal Democrat leader, Vince Cable, called on the prime minister to apologise for the Home Office crackdown on foreign students. Cable, who served in David Cameron’s cabinet alongside May, said: “We spent five years trying to persuade the Home Office that the figures they were using as evidence were bogus, but they persisted nonetheless on the basis of these phoney numbers.

“The consequences were very serious. I would hope they would not just apologise to the individual students, many of whom have paid large fees and even found themselves deported in some cases, but simply acknowledge that the figures are grossly distorted and wrong.”

The prime minister has repeatedly rejected the idea, mooted by cabinet ministers including Philip Hammond and Boris Johnson, of excluding students from the Conservatives’ target of bringing net migration down to the tens of thousands.

May has long believed that removing students from the figures would prompt accusations that she is moving the goalposts. The tens of thousands target was included in the party’s 2010, 2015 and 2017 manifestos, but Conservative governments have repeatedly failed to meet it.

Nicky Morgan, who chairs the Treasury select committee, said Thursday’s data suggested “the reasons given for including students in the net migration numbers don’t really ring true”.

Bob Neill, a Conservative MP and former minister, said: “I think there is a growing realisation in the party that it is not realistic to be counting students because it is pretty clear that the vast majority return home. And, secondly, there is a recognition that post-Brexit our education sector, our higher education sector, is a big selling point.

“We actually ought to be attracting talent. A lot of these people will go back but have connections with the UK and that works in our country’s interest in terms of trade. It is classic soft power.”

The Scottish Tory leader, Ruth Davidson, recently called for the immigration target to be dropped altogether or at least for students to be dropped from it; and former chancellor George Osborne has criticised the target as economically damaging.

Amber Rudd, May’s successor as home secretary, announced an expert review into the economic benefits of students on Thursday, which is due to report in a year’s time – and which many Conservative MPs hope will provide intellectual cover for the prime minister to change her stance.

They believe including students in the target has distorted government policy, leading the Home Office to regard the higher education sector with suspicion, rather than welcoming its contribution to the economy.

The education secretary, Justine Greening, welcomed the review as a “sensible approach” in a tweet and Jo Johnson, the universities minister, welcomed it as “good news”.

Sensible approach by @ukhomeoffice commissioning a full assessment of impact of #international students to the UK https://t.co/TgdXy0uBDq — Justine Greening (@JustineGreening) August 24, 2017

The shadow home secretary, Diane Abbott, said: “I think there’s long been a consensus on the Labour side, but also among most Tories that think about these issues, that you shouldn’t have students in migration targets. The one person that wasn’t convinced was Theresa May and I think these figures show that she’s wrong.”

May’s former senior adviser Nick Timothy argued in a series of tweets on Thursday that the fact that students were overstaying their visas was less important than those who legitimately made the UK their home after graduating.



“Exit check data shows relatively few students overstay their visa. That’s good. But debate is about how many stay in the country legally once their studies have finished. That’s why they need to be included in the immigration stats and why there is a legitimate policy debate about whether their freedom to stay and work after study should be controlled or not,” he said.

The migration data released on Thursday showed that net migration has fallen to its lowest level for three years, partly driven by an increase in the number of EU migrants – particularly those from central and Eastern Europe – leaving the UK.

The headline net migration figure of 246,000, which is the difference between immigration and emigration, was 81,000 lower than the 327,000 recorded in the March 2016, according to the ONS. Cable said the figures were evidence of an economically damaging “Brexodus” of EU workers.

Emigration of EU citizens increased by 33,000 year on year to 122,000 – the highest outflow for nearly a decade. There was a particularly sharp rise of 17,000 in departures of citizens from the so-called EU8 countries, which joined the union in 2004 – the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia. At the same time, there was a 19,000 decrease in immigration from the EU, although this is not statistically significant.

Economist Jonathan Portes said: “These statistics confirm that Brexit is having a significant impact on migration flows, even before we have left the EU or any changes are made to law or policy.”

The furore about international student numbers came as figures compiled by the Economist showed that immigration has fallen to about half what it was before the Brexit vote.

At the same time, a new report from MPs has found the “poisonous tone” of the EU referendum debate has fuelled the demonisation of immigrants and created obstacles for social integration.

The study by the all-party parliamentary group on social integration said migrants should be treated as potential British citizens rather than viewed as security threats. It recommended the councils should have a legal duty to promote integration and the government must encourage “meaningful social mixing” between immigrants and Britons, while businesses employing large numbers of immigrants should pay a levy that could be used to help ease the strains of migration on communities.

Chuka Umunna, the Labour MP who chairs the group, said: “The demonisation of immigrants, exacerbated by the poisonous tone of the debate during the EU referendum campaign, and after, shames us all and is a huge obstacle to creating a socially integrated nation.

“We must act now to safeguard our diverse communities from the peddlers of hatred and division while addressing valid concerns about the impact of immigration on public services, some of which can contribute to local tensions. We must start by valuing the contribution of all ethnic and minority communities to the UK. Rather than being seen as security risks, immigrants should be viewed as Britons-in-waiting, keen to participate in their community. The best way to do this isn’t to leave newcomers and their communities to sink or swim, but to offer migrants more support to integrate into our society.”