Curtailment of 100,000 student visas sparks row
Almost 100,000 non-EU students have had their visas curtailed by the Home Office in the past three years, figures obtained by BBC News show.
And 410 educational establishments had their licences to sponsor international students revoked in the same period.
The Home Office said it was cracking down on immigration abuse.
But the National Union of Students said international students were being "scapegoated" in order to meet targets on net migration.
The Home Office count incoming and departing international students when setting its targets on net migration, despite fears from some leading politicians that this risks harming UK universities.
The figures, released by the Home Office under Freedom of Information rules, show 99,635 students had their visas curtailed in the three years to the end of December 2015:
- 33,210 in 2013
- 34,210 in 2014
- 32,215 in 2015
Of the educational establishments that lost their licences, there were
- 199 in 2013
- 129 in 2014
- 72 in 2015
Some later had their licences reinstated - but, overall, the number of establishments holding them fell from 1,706 in 2013 to 1,405 by the end of last year.
In its response to the BBC's Freedom of Information request, the Home Office said it was unable to provide specific details of the types of institutions that had lost their licences.
But, in a statement, it said the revocations had been focused on "poor quality institutions".
During the period, no universities had their licences revoked - though a few had them temporarily suspended.
A Home Office spokesman said, since 2010, it had "cracked down on immigration abuse from poor quality institutions which were damaging the UK's reputation as a provider of world-class education, whilst maintaining a highly competitive offer for international students who wish to study at our world-leading institutions".
He said the strategy was working.
"Visa applications from international students to study at British universities are up by 17% since 2010, whilst visa applications to our elite Russell Group universities up by 39%," he said.
"We will continue to reform the student visa system to tackle abuse and deliver an effective immigration system that works in the national interest."
Where leave to remain is curtailed, individuals are given 60 working days' notice and "are encouraged to depart voluntarily", according to the spokesman.
"It they fail to do so enforcement action can be taken," he added.
But Dominic Scott, chief executive of the UK Council for International Student Affairs (UKCISA), said: "If these figures are correct, then they show that the Home Office's action against students has been even more draconian than previously understood.
"And many fear of course that it may have been more in pursuit of meeting a net migration target than addressing real abuse."
NUS international students' officer Mostafa Rajaai said the "shocking" figures were "clear evidence the Home Office is following a political agenda, rather than trying to remove real cheats".
"It has a clear disregard for the right to a fair trial and the past six years have seen the steady erosion of international students' rights within the UK," he said.
Mr Rajaai quoted NUS research suggesting most non-EU students thought the government was unwelcoming towards international students.
"If the government continues to scapegoat overseas students in order to hit its immigration targets, the damage to the UK's reputation as a desirable place to study will only worsen," he said.
"The only solution is for immigration targets to be scrapped completely."
According to official figures, 201,763 students applied for UK study visas last year.
- 166,366 at universities
- 15,982 in further education
- 2,930 in English language schools
- 13,675 in independent schools
According to an Office of National Statistics published in January, 192,000 international students arrived in the UK for long-term study in the year to June 2015 - down from a peak of 238,000 in 2010.
Most of this fall has been in further education, says the ONS, and is due to the tightening of immigration rules.