Academics at five Welsh universities have been forbidden from supervising PhDs at the University of Wales, as they compete with their own institutions' doctorates.
The St David's Day Group - composed of Aberystwyth, Bangor, Cardiff, Glamorgan and Swansea universities - have agreed to not support the Prince of Wales PhD studentships, which are validated by the University of Wales.
David Halton, Glamorgan's vice-chancellor, has written to staff saying that permission is unlikely to be given for activities that compete with Glamorgan's own.
"I understand that some members of academic staff may have been approached to externally supervise Prince of Wales PhD students validated by the University of Wales," he said.
"This university has never been part of the University of Wales and has recently joined the St David's Day Group. All members of that group have agreed they would not support the University of Wales' PhD scholarships, particularly given the fact that, collectively, the group will be offering a range of PhD scholarships in the very near future."
Academics are usually allowed to work for other universities in their own time, provided they declare any such activity and are given permission.
However, Professor Halton wrote: "It is highly unlikely that any member of Glamorgan's staff will be given permission to supervise these University of Wales studentships."
A member of staff at Glamorgan, speaking anonymously, said this message "strikes at the very heart of what we represent as academics" and was a "clear attack on academic freedom".
"If senior managers are stopping us from working with other Welsh institutions, the next step will be to stop academics from pursuing political action," the employee said.
"We are worried that the university is destroying its hard-fought reputation as an independent organisation willing to work with anyone in exchange for a place at the table with the 'big boys'."
The member of staff described the other universities in the St David's Day Group as "research obsessed" and "more interested in their own narrow, self-serving missions than in helping the country to get out of its current predicament".
A Glamorgan spokesman responded: "It is important that Glamorgan's academic staff are available to supervise the (St David's Day Group) PhD students."
Announcing their intention to collaborate as a group earlier this year, the five universities said in a joint statement: "Our first priority will be to help Wales work its way out of the current recession and, beyond that, to create a vibrant knowledge-led society and economy that puts Wales ahead of the game."
Together, the five universities in the group represent more than 70 per cent of all students in Wales and more than 95 per cent of the nation's research activity.
The University of Wales declined to comment.