Scottish universities are predicting a legal battle over the government's decision to make English, Welsh and Northern Irish students pay more than Scots in tuition fees for a four-year honours degree.
Scottish principals are today expected to call on the Committee of Vice Chancellors and Principals to back their campaign for equitable treatment across the United Kingdom.
But the government says there are no plans for further fee waivers and is urging more non-Scots to seek direct entry to the second year of Scottish courses, gaining a degree in three years.
Students living in Scotland will pay a maximum Pounds 3,000 in tuition fees for a four-year honours degree, in line with honours degree costs south of the border.
This waiver will apply to European Union entrants, but students from elsewhere in the UK will face a Pounds 4,000 bill.
Sir Stewart Sutherland, principal of Edinburgh University, told the Committee of Scottish Higher Education Principals' forum that the decision was "a minefield".
"I think it will end up in the European courts because students from England, Wales and Northern Ireland are part of the EU too," he said.
Scottish higher education institutions are dismayed by the prospect of any threat to the cross-border flow, which currently brings in almost 13,000 students annually.
Andrew Miller, principal of Stirling University, warned of a "cascade down", with institutions that traditionally attracted English students trying to recruit Scots who would normally go to other institutions.
But Scottish education minister Brian Wilson told COSHEP he believed the move would not discourage cross-border flow.
Students from less well-off families would not pay tuition fees, while the better-off, whose parents already contributed to an extra year's maintenance, were unlikely to be deterred.
"There will also be a large group of students who could, more readily, be admitted as a result of their A levels into the second year of Scottish courses. At present, only 10 per cent of this group take up this option, but many more could and should be encouraged to do so," he said.
Many Scottish faculties can offer second-year entry to A-level students, since entrance requirements are based on Scottish Highers which can be taken in only one year.
Sir Ron Garrick, who chaired the Dearing inquiry's Scottish committee, said he had queried the low proportion of second-year entrants, and was told the A-level students themselves wanted to take the full course.
Statistics revealed that students from south of the border taking a four-year course gained "markedly better qualifications than the average" and "very worthwhile jobs", Sir Ron said.
"That to me sounded like a wonderful selling point for the Scottish institutions - do the four years because look at the results you get," he said.
If A-level students wanted to come for three years, it was up to institutions to begin to recognise the value of their qualifications.
l An Edinburgh University students' association survey of 500 new students has found that 45 per cent of Scots and 44 per cent of students from the rest of the UK thought the government's proposals on tuition and maintenance awards would discourage them from studying for a four- year degree.
Edinburgh is setting up 50 bursaries of Pounds 1,000 annually for Scottish entrants from next session, half aimed at students from local state schools and colleges, and half at "the most academically able".