The College Lecturers' Association says plant bargaining in each FE college has led to a growing disparity in salaries, which will eventually harm pensions.
The association, part of the Educational Institute of Scotland, claims the gap at the top of the lecturer grade between staff in the best paid and least well paid college stood at pound;2,238 last October.
The CLA says pay levels are now having a negative effect on recruitment and morale, with annual awards paid a year in arrears in almost all cases. In some colleges part-time lecturers on "grossly inferior contracts" do as much as 50 per cent of teaching.
Mike Fuller, regional officer with the Manufacturing, Science and Finance union, suggests that the time is ripe for FE staff to mount a challenge, following a court ruling in England affecting Health Service trusts that it is not necessary to work for the same employer to pursue equal pay claims, so long as the work is in a related activity.
"We need to establish the principle that people who do similar work in FE are paid similarly," Mr Fuller said.
Jim Cassidy, the CLA's president, would not be drawn on whether the union is prepared to take on management but said that Mr Fuller "has provided us with food for thought".
More controversially Mr Fuller, in an address to a recent FE conference in Glasgow, called for an end to differences in terms and conditions for academic and support staff in colleges.
"The distinction between blue and white collar staff only survives in the public sector," he said. "Staff should justify themselves solely according to their skills and qualifications and where these place them on the pay scale."
Mr Cassidy said the CLA rejected "single-table bargaining".
FE Focus, page 34