The University and College Union fears that employers want to force it out of running the sector's £30 billion pension scheme after its chairman raised the question of whether joint governance was "fit for purpose".
During a recent closed meeting of vice-chancellors, Sir Martin Harris, chairman of the Universities Superannuation Scheme board, floated the question of whether institutions would press for an employer-run scheme. That brought an angry response from the UCU, whose members last week voted to hold "sustained industrial action" from next month at 67 older universities in protest against cuts to pensions.
The UCU - whose predecessor, the Association of University Teachers, founded the USS with the employers in 1974 - acts as sole representative for the scheme's 140,000 active members.
Sally Hunt, the union's general secretary, said that following the employers' successful move to end final-salary pensions for new entrants to the USS, "the next item on their agenda looks to be to reduce benefits for all to the lowest common denominator, and getting rid of the UCU would no doubt make that much easier.
"Given the total loss of credibility of the employers among staff in recent months, how many of the current employer representatives on the board would survive if they were elected by one fund member, one vote rather than through patronage?"
The UCU and Universities UK - the employers' representative - each hold half the seats on the USS Joint Negotiating Committee (JNC), which decides on any changes to benefits, as well as appointing three and four scheme directors respectively.
During the current dispute over scheme changes, the USS threatened High Court action against the UCU's representatives over their refusal to attend JNC meetings, which delayed final approval for the changes.
Sir Martin, a UUK appointee, raised the prospect of radical change when he spoke at the scheme's institutions meeting, held during the recent UUK conference.
He is understood to have posed the question of whether the employers would judge the current joint model "not fit for purpose" and decide they should direct the scheme, advising them to give the USS their views.
A USS spokesman said Sir Martin had "confirmed the factual position, which is that changing the governance arrangements is not a matter for the trustee board", and had said "categorically that any changes in the overall balance of the scheme lay with the stakeholders".
The Employers Pensions Forum said it did not want to see the USS become an employer-run scheme and confined itself to commenting on the internal USS review, which Sir Martin has made clear will cover only refinements to the existing structure rather than any change in the balance of power.