The government rejects claims that a crackdown on immigration could harm British universities and cost the economy billions of pounds a year.

In a letter to the prime minister, nearly 70 university heads are warning that changes to student visas would drive bright applicants away.

They urge the government to take foreign students, who bring in £8bn a year, out of net immigration counts.

But ministers said the policy did not stop genuine students coming to the UK.

Immigration Minister Damian Green said the government was "determined to prevent the abuse of student visas as part of our plans to get net migration down to the tens of thousands."

"Students coming to the UK for over a year are not visitors", he said. "Numbers affect communities, public services and infrastructure."

In the letter, senior education figures called for the prime minister to class foreign students as temporary rather than permanent migrants.

But Mr Green pointed out that the Independent Office for National Statistics was responsible for producing net migration figures, which were based on an internationally agreed definition of a migrant - someone entering the country for more than a year.

"Public confidence in statistics will not be enhanced by revising the way the net migration numbers are presented by removing students", he said.

In their letter, the signatories expressed concern that Britain's higher education industry could be harmed by changes to immigration policy.

Britain attracts around one in 10 students who study outside their home country, generating around £8bn a year in tuition fees, they said.

This, they added, could increase to £17bn by 2025.

But the heads warned the government's immigration policy risked driving international students to the United States, Australia, Canada and Germany.

The letter was signed by Sir Menzies Campbell, the former Liberal Democrat leader and chancellor of St Andrews University, and the broadcaster and chancellor of the University of Leeds, Lord Melvyn Bragg.

Other signatories include the former Conservative minister and chancellor of the University of Hull, Virginia Bottomley, and Patrick Stewart, chancellor of the University of Huddersfield.

Figures released on 24 May revealed that annual net migration to the UK is currently 250,000 - still double the government's target of fewer than 100,000 people a year.

The most common reason for people coming to the UK is to study, as in previous years.

Recent visa changes include rules that prohibit international students from bringing their dependents with them - unless they are enrolled on a postgraduate course of at least 12 months.

A "more selective" system has also been put in place for students wishing to stay and work in the UK, after they finish their course.----

Source: http://www.bbc.co.uk/news/uk-18259626