Unions representing staff at Glasgow Kelvin College have written to members to highlight "deep concerns" over recruitment for the next academic session.
The newsletter from the Educational Institute of Scotland (EIS), which incorporates the Further Education Lecturers Association, said some courses were well below expected levels while others were oversubscribed.
A spokeswoman for the college accepted some issues had been encountered earlier in the year, but said recruitment levels were now where expected with some 4,500 offers made out of a total capacity of 5,000 full-time students.
Glasgow Kelvin College was formed in November last year after the merger of John Wheatley, North Glasgow and Stow colleges as part of a Scotland-wide programme of re-organisation.
The union newsletter to staff states: "While some courses are well below target at this stage of the year others are already over-stuffed, with the threat of serious workload issues for teaching staff next session not to mention the impact on the learners of being crammed in like sardines - or, worse still, turned away.
"In other areas, staff are nervous about whether courses will run at all ... because learners have not been interviewed, have been wrongly sent rejection letters, have been sent letters for mysterious interviews the staff know nothing about or all of the above, sometimes all on the same day."
A college spokeswoman said: "We recognised that, due to mid-session merger and restructuring, there was an impact on recruitment and admissions procedures for session 2014/15. Action was taken from April to address these issues and recruitment is now approximating expected levels for this time of year."
She said the college was involved in "extensive consultation" with EIS officials and said the matter had been discussed with them at a board of management meeting in June.