Jobs are under threat at Barnsley College as part of major changes across 11 departments.
Staff were given just days to decide whether to apply for voluntary severance terms, with the final deadline running out today.
The restructuring is aimed at saving the college around £600,000 and staff not only face redundancies but pay cuts too.
It is believed some workers may end up facing salary reductions of up to £12,000 a year.
Union officials are warning the dispute could result in a ballot leading to possible strike action.
Around 800 staff are employed at the college and principal Colin Booth said staff were being consulted throughout the restructuring process.
He added: “We anticipate at this stage that there may be a reduction in staff of between 10 and 15 through voluntary measures.”
But Lee Short, UCU joint branch secretary for the college, said the figure was likely to be 20 if not more, as not all attempts to redeploy staff would be successful.
And he said asking staff to make life-changing decisions on voluntary severance in such a sort time showed a lack of concern.