The five-page letter from Paul Mackney, NATFHE general secretary, catalogues 18 fundamental differences with the Association of Colleges and calls on ministers to back a full review of FE through a commission representing both sides with an independent chair.
Solutions to wide-ranging disagreements over pay and conditions were still being sought, he says. He accuses the association of indulging in the worst excesses of industrial relations that epitomised the years of its disgraced former leader, Roger Ward.
"I regret to say that I am not over-confident of constructive and imaginative approaches to solutions given that the current negotiators appear to adopt an approach similar to that adopted in the years of Roger Ward," he says in the letter.
Mr Mackney attacks the AOC board member most closely associated with Mr Ward.
"The AOC has the same employment committee chair, Colin Daniels, as in those days. It has singularly failed to appreciate the lecturers' workload (teaching hours) issue."
Nevertheless, in some respects relations are improving between the two sides. An accord has been reached at officer level. David Gibson, the new AOC chief executive, has also written to Mr Mackney seeking wide-ranging talks.
But the issue of teaching hours is still the key to industrial peace. "The AOC has refused to make an improved offer on the 22-27 weekly teaching hours range rejected by our members last autumn," Mr Mackney tells ministers.
"That offer appears to have been withdrawn, yet the AOC seems unable even to recommend local negotiations on workloads in the absence of a national resolution."
Mr Mackney must balance continued negotiations with pressure for radical action by his members at a national conference in London on pay and conditions next week.
An influential minority of NATFHE's national executive will press for moves to all-out strikes.