Britain's biggest trade union this week claimed there was an "institutionally racist" culture at Manchester Metropolitan University. It accused management of failing to act despite repeated warnings over several years.
Unison said it had been raising concerns about a racist culture at MMU for more than five years with little effect.
The university hit back, pointing out that its race equality procedures were last year commended as "exemplary" by the Higher Education Funding Council for England.
Unison's claims were made as The Times Higher learnt that seven separate discrimination complaints from MMU staff are pending at a Manchester employment tribunal to be held this year.
A university spokesman said that while there were seven pending tribunal complaints, the university had 4,242 staff and still hoped to resolve five complaints internally without recourse to the tribunal. "Obviously, that is seven too many, although we have seen the number of complaints lodged rise since the introduction of the dispute regulations," he said.
But documents leaked to The Times Higher also show mounting concern about race-related incidents, racist literature and the use of racist language on campus.
Paul Foley, Unison's regional secretary for the North West, said racism was "the most important issue" for the union at the university, despite crucial talks over the new pay framework and job grading structures.
"Unison has for a number of years been raising the issue about what we see as an institutionally racist culture," he said.
"We have been asking the university to tackle this. We have had a number of grievances from black staff, a number of disciplinary cases involving black staff and have a number of tribunal cases. We have been saying that they need to start tackling this issue in a very proactive way, but we are frustrated that we have seen very little improvement."
An internal document seen by The Times Higher shows that in March 2004 a black member of support staff at the university's Aytoun Street campus, which houses the Business School, was disciplined over a race-related incident.
Bill Hallam, MMU's head of human resources, handed the staff member a written warning for behaving in an "intimidating and aggressive manner" towards a colleague.
But he said the disciplinary panel had taken "into account... the points that were made on your behalf in relation to there being a racist culture at Aytoun Street".
Mr Hallam added that the panel had heard from a number of witnesses about racism among some manual staff at Aytoun Street. "I want to assure you that notwithstanding the outcome of this disciplinary hearing... I recognise this is an issue that must be tackled."
In December last year, Mr Foley complained to the university's employee relations manager, Peter Gibbs, about racist material posted on noticeboards.
The union representative said that the university had been quick to act against a controversial anti-racist poster that had been put on Unison's noticeboard without the union's endorsement, but in contrast it had been slow to react to a "racist poem" that had been "pinned up in various locations in Aytoun Street".
"It was in prominent positions yet it was not removed by security or management. I believe no investigation has taken place," Mr Foley said.
"Similarly, I understand that no investigation has taken place or corrective action taken to the exposure of racist language and derogatory terms to describe Asian people."
A spokesman for the university said it had not been approached by Unison about the poem at the time and he stressed that it did not tolerate such literature being displayed around the university.
The spokesman added that the university had not accepted that a racist culture existed on campus, but he "recognised that there was an issue".
There have been a number of initiatives to "build on good employee relations", including the establishment of a charter last May setting out standards of behaviour and a training programme for staff. A workplace survey is planned for next month.
The spokesman said: "Overall, the university believes it has a decent record on racial issues in the workplace (no cases have been successfully brought at tribunal) and our equal opportunity and racial equality policies were deemed "exemplary' by the funding council in 2004.
"Nevertheless, the university will not be complacent."