Swansea University is to become the first university to take legal action against the Association of University Teachers. It has instructed solicitors and counsel to carry forward a threat to sue the union for libel.
The move is the latest blow from Richard Davies, Swansea's vice-chancellor, in a year-long dispute against local AUT leaders who oppose department closures at the university.
Solicitors Morgan Cole, acting for Swansea, have threatened libel action against the national AUT over 45 allegedly defamatory passages contained in the local AUT's petition to the visitor on the closures.
In a letter to the national AUT, lawyers argue that the petition and other documents submitted to the visitor "contain statements of fact, innuendo and comment" that, taken together, imply that Swansea is being governed in a fraudulent manner and in "bad faith".
The national AUT, which local union leaders say has been "extremely rattled" by the threat, has been forced to withdraw an advertisement for the petition from its website.
But it has yet to respond to a demand from the university that it accept the disputed passages in the petition as false and make a public apology.
Both sides have refused to comment as they negotiate the terms of a meeting to consider how to settle the issue.
But the talks may be held up by the intervention of Philip Havers QC, who took over as Swansea's visitor last year after Neil Garnham QC made history by stepping down in the middle of handling the dispute.
Mr Havers, brother of actor Nigel, has invited new submissions in the light of the legal action.
The local AUT has argued that the action is in contempt of the visitorial process.
It says: "The respondents' threat to bring a libel action against the national AUT raises the prospect of the same matters being adjudicated upon in two 'courts' simultaneously.
"If the threat is implemented and litigation begun, the purpose would include seeking to induce the national AUT to make statements that would be highly prejudicial to the visitor's investigation and an unwarrantable interference with the conduct of proceedings and our right to petition."
Local union leaders also claim that legal costs associated with the petition, which by the end of September last year had reached £68,794, have been sanctioned by the vice-chancellor's office and university finance committee rather than Swansea's governing body.
Their submission to the visitor states: "The petition contends that senior officials, especially the vice-chancellor, have acted improperly and in breach of the university's charter and statutes and its regulations. The vice-chancellor has already spent enormous sums on defending himself against these charges. The university is footing the bill."
Swansea said this week that the "restructuring" of departments, which has been opposed by local union leaders, had enabled it to invest in the development of one of the world's most powerful computers.
The computer, called Blue C, will be part of a £50 million Institute of Life Sciences at the university, due to open in 18 months.
The institute will host a European Deep Computing Visualisation Centre for Medical Applications, researching solutions for healthcare treatment, medicine and disease control, and is expected to create 238 new scientific posts.
Blue C, built and part funded by IBM, will be the size of a tennis court, and will be capable of making calculations in seconds that existing machines take hours to complete.