Headteachers and unions fear that the Scottish Government will follow the Chancellor of the Exchequer's example and axe the education maintenance allowance (EMA) for 16 to 20-year-olds from poor families.
The UK-wide scheme, which was piloted in Scotland in a bid to keep children from disadvantaged backgrounds in education after the age of 16, is to be reviewed next month by the Scottish Government.
George Osborne announced last week in his comprehensive spending review that savings from "replacing" the EMA in England would be pound;0.5 billion. He will use the money to raise the participation rate in education to 18 and fund a replacement programme of targeted support for all under-19s.
Although his announcement covered only England, the Scottish Government had announced a review of the EMA for December. It is now widely expected to deliver a knock-out blow to the scheme, which currently benefits 39,000 Scottish students and costs pound;35 million.
Scottish ministers have already begun to erode the full scheme. Last year, they cut the EMA budget by 20 per cent and changed its eligibility criteria by lowering the threshold for the pound;30-per-week payment and axing the pound;10 and pound;20 payments altogether.
Scottish recipients can now apply for the payment only up till Christmas; in previous years, their payment covered the whole of the academic year.
Brian Cooklin, past-president of School Leaders Scotland, fully expected EMAs to be withdrawn in December. "They have gradually been whittling it away," he said.
Jim Thewliss, the head of Harris Academy in Dundee, who will become SLS president next month, made the same prediction. He said that a number of his pupils would have struggled financially to pursue their education, were it not for access to an EMA.
Any move to remove EMAs would be "regressive", he warned.
But Mr Cooklin, head of Stonelaw High in Rutherglen, South Lanarkshire, said he did not believe the EMA scheme was "affordable" in the current economic circumstances where frontline services were being hit.
Nor was it "doing its job", he said: "It was supposed to stop people taking part-time jobs so they could concentrate on their studies. There is not much evidence that's the case."
EMAs were a good thing if youngsters used them to leave school or college with enhanced qualifications - but not if they were just "treading water". "Some colleagues complain that young people just have to be present, but don't have to apply themselves, to receive an EMA," Mr Cooklin added.
Most students earn the discretionary pound;150 bonus, payable in January and June, for meeting certain targets, but headteachers could and did refuse to pay bonuses to pupils who consistently turned up late, did not wear uniform and did not do their homework. Mr Cooklin said he had refused the bonus to fewer than 10 pupils per year who were eligible for the EMA.
Both the Educational Institute of Scotland and the Scottish Secondary Teachers' Association warned that withdrawal of the scheme could lead to lower participation in post-16 education.
Ann Ballinger, SSTA general secretary, acknowledged that some pupils misused the pound;30 weekly payment, and said it should be payable on favourable teacher reports.
The Department of Education in England said evaluations showed that 90 per cent of the money was going to students who would have stayed on anyway.
But an Institute for Fiscal Studies report said the EMA was a significant factor in improving staying-on rates, particularly for boys and for the poorest students. It said the EMA had boosted participation in education by around six percentage points.
The fears about post-16 participation come as the university admissions service UCAS published figures showing that the number of applications for 2011-12 to higher education institutions in Scotland is almost 9 per cent greater than at the same period last year.
The number of full-time undergraduate university places in Scotland fell by more than 10 per cent last year, from 40,690 in 2009 to 36,592 this year.