Steven Schwartz, vice-chancellor of Brunel University, was at the centre of a row this week after he publicly accused two staff members of making "unwarranted demands for money" by taking his university to employment tribunals to claim race discrimination.
Professor Schwartz, who is the Government's adviser on widening access to universities, was attacked by the Association of University Teachers. It said his allegation against the two staff was "completely untrue".
In an open letter to Professor Schwartz, Sally Hunt, the AUT's general secretary, says his comments have caused "great distress" to the two staff.
Ms Hunt said that Professor Schwartz's comments raised "issues of great concern and importance about the rights of our members at Brunel to challenge racism in the workplace and to seek support from their union without fear of victimisation and public criticism by their employer".
The AUT said that it was taking legal advice over the vice-chancellor's refusal to withdraw the comments and apologise.
Although he did not name the staff members, it is understood that Professor Schwartz was referring to race discrimination claims made by Saeed Vaseghi, professor of engineering, and Gurdish Webster, from the university's computing services department.
A third race discrimination claim against the university, from the university's former director of marketing, Harinder Bahra, was heard in December but the result is pending.
Both Professor Vaseghi and Ms Webster initially lost their claims, but both successfully appealed the decisions.
In Ms Webster's case the original tribunal found, as a matter of fact, that the term "Paki" was used by a member of staff at Brunel, and that Ms Webster had received racist emails referring in one case to a "smelly Indian".
She made legal history, clarifying discrimination laws, with a successful appeal against the original judgment that was welcomed by the Equal Opportunities Commission. The appeal was, however, later overturned by the Court of Appeal.
Rakesh Patel, head of the London employment rights department at solicitors Thompsons, who represented both complainants, said: "The university conveniently forgets the findings of fact. Tribunal rules are very clear - that either party can seek costs if a claim is misconceived, or unmeritorious, and Brunel did not seek costs."
In his March report to staff, Professor Schwartz says he is "dismayed" that the two cases were taken to appeal and that the AUT had written about the Webster case in its members' magazine in a "sensationalist" way - claiming the union was "pushing the boundary on race discrimination".
"I am sorry to say that my hope for a more constructive engagement with the AUT was in vain," he comments.
He says that the cases have cost the university £60,000 to defend, and adds: "This is money that could have been used for teaching and research."
This week, Ms Hunt told The Times Higher : "Neither case can be described as 'without merit' - don't take my word, look at the actions of the employment tribunal in each instance, with both cases allowed to proceed and no costs awarded against the AUT.
"Since Professor Schwartz has chosen not to withdraw his public and inaccurate comments, we are taking further legal advice and actively considering reference to the Commission for Racial Equality."
A spokeswoman for Brunel said that the university would not debate the content of Ms Hunt's letter in the pages of The Times Higher , but added:
"We are pleased that the employment tribunals found in our favour - both cases were vigorously defended and the judicial process has been successful.
"We remain totally committed to our policy of race equality (which won Exemplar status from the Higher Education Funding Council for England in 2003) and to open communication with staff."
* Lecturers will strike in protest at planned job cuts at Brunel University, the AUT confirmed this week.
Members at Brunel voted 71 per cent in favour of strike action, and 77 per cent in favour of action short of a strike, in protest at plans to axe 60 jobs at the university, possibly including some compulsory redundancies.
The turnout was 52 per cent. The union said a one-day strike would take place next month.