Organisers of a vote of no confidence in the vice-chancellor of London Metropolitan University, Brian Roper, could face criminal and civil proceedings over how the ballot was conducted, the university claimed this week.
Lecturers' union Natfhe and support staff union Unison have carried out a ballot of staff over their confidence in the management of Professor Roper and Lynn Link, the head of human resources.
But it emerged this week that the results are being withheld amid legal concerns over the unions' access to staff details and over the "offensive" content of a letter attacking the two managers.
In a statement this week, London Met said: "The university and the Electoral Reform Society, which conducted the ballot on behalf of Natfhe and Unison, received numerous complaints about the ballot, with regard to the unauthorised use of personal details of non-union members and also the content of the accompanying material, which caused offence.
"These irregularities are now the subject of investigation by the university, the Information Commissioner and the Electoral Reform Society.
"The Electoral Reform Society have issued a statement disassociating themselves from the content of the material that accompanied the ballot and have suspended issuing the result of the ballot until these issues are clarified.
"Given the possibility of both civil and criminal proceedings against the organisers of the ballot arising from these investigations, it is not possible for the university to comment further at this time."
A two-page letter that accompanied the ballot papers, and which were signed by both Natfhe and Unison, attacked the management of the university and blamed Professor Roper and Ms Link directly for problems at the university.
Natfhe engaged in one of the longest industrial disputes against London Met last year over the attempted imposition of new contracts for staff of the former London Guildhall University, following its merger with the University of North London.
The union's letter said that much of the potential of the 2002 merger had been "squandered" and that the university "suffers from an authoritarian, defensive management style".
Roger Kline, head of universities at Natfhe's national office, was expected to criticise Professor Roper personally in his address to Natfhe's annual conference this week.
He was expected to tell delegates: "Brian Roper threw court injunctions, dismissal notices, pay deduction and the kitchen sink at us. He failed."
He will continue: "We ended up with almost precisely the contract of employment that Professor Roper had wasted vast resources opposing.
"Now, following a letter from Eversheds [the university's lawyers], we can't even publish the results of a ballot on a vote of no confidence in him and his human resources director."