Not so long ago, the Work and Pensions Secretary, Iain Duncan Smith, echoed Gordon Brown's nadir in calling for British jobs for British workers. "In the short term, controlling immigration is critical," he said, "or we will risk losing another generation to dependency and hopelessness."

Like Brown, Duncan Smith failed to offer a realistic solution to the perceived bias of the labour market towards those from abroad. He complained that more than half of new jobs in the preceding year had been taken by foreigners (a statistic dismissed as "dodgy" by Matt Cavanagh of the Institute for Public Policy Research, who put the figure at closer to 10 or 20 per cent). In response, business leaders, rather sensibly, urged the coalition government to focus on reforming skills and education.

The most recent Tory assault on UK colleges, however, probably isn't what they had in mind. The Conservatives are committed to slashing net migration from 239,000 per year to below 100,000 (by next election season, naturally) -- but since a large proportion of immigrants to the UK come from within the European Union and are not subject to British control, ministers have little wriggle room.

Of non-EU immigrants, many are here to work; yet this group, so necessary to UK business interests, has largely been protected. That leaves foreigners arriving to join their families -- an entry route safeguarded by international and human rights laws -- and students. The Tories have predictably leapt upon this last group, even though they contribute in excess of £5bn to the UK economy each year through tuition fees and off-campus expenditure.

When the government unveiled its new student visa rules in March, Sally Hunt, general secretary of the University and College Union, raised concerns that they risked "sending out the worrying message that the UK is closed for business". If the UK as a whole has managed to remain open (well, barely), the same cannot be said for the 51 colleges that have failed UK Border Agency inspections and the more than 470 education providers that have been barred from accepting new foreign students in the past six months alone, according to new figures from the Home Office.

The Immigration Minister, Damian Green, is correct to come down hard on the "widespread abuse of the student visa system" and many of the colleges that were closed were doubtless shut for good reason. As the Financial Times reports: "When asked by inspectors, one of these providers could not even produce a list of students enrolled or a timetable of classes, while others could not produce records of student attendance."

Yet Green's jubilance that the measures are "beginning to bite" is misplaced.

The above successes aside, the Tory programme of targeting prospective students from outside the EU has been poorly conducted and ill-considered. Despite the symbolic value it will have to some, it will fail to make "a significant dent" in the immigration reduction target, according to Scott Blinder, senior researcher at the Migration Observatory at the University of Oxford.

Instead, as a result of new government rules, a higher education sector that is heavily reliant on international students (and which has already experienced a fall of 9 per cent in UK applicants, likely due to the massively increased fees) is deterring bright, young people from around the world from choosing Britain. The UK Universities group, a student placement service, reports a sharp downturn in applications from abroad; many are instead opting for countries such as Australia, New Zealand and Canada.

A Migration Observatory poll found that 57 per cent of Britons were happy with the number of foreign university students rising or staying the same. The figures in relation to English language or further education students were also positive. So does it make sense to target them? Visa abuse within the sector is very low. It's just odd to overstate the case. In a recent FT report, Cavanagh says: "The public are negative about immigration but they don't mind foreign students or skilled workers. Yet those are the two categories that the government is ending up bearing down on the hardest because they're the easiest to control."

It's time that the government prioritised the national good over easy headlines. Perhaps Nicola Dandridge of Universities UK was on to something when she suggested:

The numbers of international students coming into the country should be accounted for separately and not included in the definition of net migrants for the purposes of government policy. International students are not economic migrants. They come to the UK to study, and then they leave. The vast majority of international students return home once their studies are completed, and those that do not, need to re-apply for a separate visa.

Sounds like common sense to me. The US and Australia both attempted to curb the numbers of overseas students but reversed the policy, after it damaged the international competitiveness of their institutions. We should learn from their mistake.