THERE is growing concern in the university sector about a fall in the number of foreign students coming to study in Scotland from some key countries, so much so that some university and business leaders have written an open letter to the Smith Commission making the case for the immigration rules affecting Scotland to be changed.

The letter, which is published in The Herald today and is supported by Universities Scotland and the Scottish Chambers of Commerce among others, calls on the commission to consider including some control of immigration in the greater powers that will be handed to Holyrood. The signatories to the letter would also like to see the new powers being used to allow international students to be allowed to work here for two years after they finish their studies.

The case for change made in the letter is logical and fair. In recent years, Scottish universities have seen a dramatic fall in the number of postgraduate students from some overseas countries (in some cases, nearly 50 per cent) and that is undoubtedly bad news for the university sector and wider society.

For the universities themselves, the most obvious effect is that they are losing a large proportion of a vital income stream (overseas students pay up to £17,000 a year in fees and last year accounted for 12 per cent of universities' total income).

There are also consequences for Scotland as a whole, with overseas students contributing millions of pounds to the economy, something which Labour recognised in 2004 when then First Minister Jack McConnell launched his Fresh Talent initiative, which gave overseas students the right to remain in Scotland for a time after graduation. But more recently, the bogus college scandal has led to the Home Office toughening up visa restrictions, something which is now hitting overseas student numbers.

The clampdown on bogus colleges had to happen, but what the current rules do not recognise is that Scotland and England have different needs, and attitudes, on immigration. The authors of today's letter point out Scotland faces the serious demographic challenge of an ageing population, which a healthy number of educated, skilled postgraduate students could help address.

They also point out that public opinion in Scotland is different. A recent study found there was a large body of anti-immigration opinion here, just as there is in the rest of the UK, although polls in Scotland show only a small minority wanting to control highly skilled workers or students coming to the country.

Opinion polls also show that the majority of Scotland believes immigration should be the responsibility of Holyrood, which, combined with the views of today's influential correspondents, make a strong case for the Smith Commission to consider including some control over immigration in the extended powers. At the very least, the rules on immigration should include an exemption for genuine overseas students, for the sake of our universities but for the sake of the country as a whole.