The number of students gaining access to higher education through part-time college courses has dropped by 43 per cent in the past decade to just 16,455, new figures reveal.
The total number of HE students in colleges has also fallen significantly, from 55,610 in 2003-04 to 47,795 in 2012-13, according to statistics published by the Scottish Funding Council (SFC).
Colleges provide a large proportion of all HE delivered in Scotland and are key in opening up access to students from the most deprived backgrounds. In 2012-13, 586 students received degrees in colleges, compared with 115 in 2003-04.
The Scottish government has asked colleges to prioritise full-time courses, as well as the 16 to 19 age group, to tackle youth unemployment. But student representatives fear that this could exclude those who need a college place the most.
Stacey Devine, NUS Scotland women's officer, said the full-time emphasis was particularly affecting women, who were "more likely to want, and need, to study part-time due to caring responsibilities", adding: "Having a focus on full-time places can only work in practice if the support is there to ensure students are able to take them up."
The SFC figures also reveal that the number of students on Higher National Certificate (HNC) and Higher National Diploma (HND) courses - an important access point into HE for many - have fallen by 10 per cent, from 44,275 in 2003-04 to 39,745 in 2012-13. Conversely, the number of students gaining one of those two qualifications rose from 18,520 to 20,535.
Ms Devine said that HNCs and HNDs were "a really important and distinct feature of Scottish higher education". While they were valid qualifications in their own right, through articulation they provided a route into university for thousands of students who might otherwise miss out, she explained.
"At a time when the focus is rightly on fair access, we cannot underestimate the importance of HNCs and HNDs and articulation [gaining access to the second or even third year of a university course] as a key way to boost the numbers of students from our most deprived backgrounds, who make up a fifth of students who do articulate," she said. "It would be worrying if the number studying for an HNC or HND meant that articulation was being compromised, and we'd want to see colleges and universities working together to further strengthen the opportunities for students to go through that route."
NUS Scotland also raised concerns over what it called a gender split within STEM (science, technology, engineering and maths) subjects, which it claimed was more pronounced in colleges. "We'd be worried that women will face being squeezed out as a result of prioritising full-time courses, and there needs to be a coordinated effort to get more women into Stem at all levels and in a way which meets their needs," Ms Devine said.
John Henderson, chief executive of Colleges Scotland, said: "The Scottish Funding Council's figures reflect the trend in the reduction of part-time courses and opportunities for adult learners in colleges. It is vital that we expand these to meet the needs of learners and the Scottish economy."
A Scottish government spokeswoman said that colleges continued to play a key role in HE, with more than a quarter of entrants choosing to study at the institutions. "The number of students leaving college with HNCs and HNDs is up 36 per cent since 2007-08 and the number getting degrees is up 121 per cent over the same period," she added. "Colleges continue to deliver for Scots from all backgrounds, with 24 per cent of HE entrants in 2012-13 coming from deprived areas.
"Colleges are focusing on courses - largely full-time - that deliver the skills and qualifications people need to get a job and develop their careers, in line with the government's priority of supporting people into work. Our commitment is to maintain full-time equivalent student numbers and colleges have exceeded that commitment this year."