Senior managers at the 1,000-pupil Nicolson Institute in Stornoway, where the school board has taken the unprecedented step of resigning en masse, could be swept away if the Western Isles Council approves a merger with the neighbouring Lews Castle School.
The unions believe that a clear-out of the Nicolson's top management has been the council's real intention since it became embroiled in the row over bullying that erupted after last year's suicide of Katherine Jane Morrison, a 16-year-old Nicolson pupil.
The creation of a combined institution would require senior staff at both schools to apply for their own jobs. Neil Galbraith, the council's director of education, confirmed that a merger would be proposed if next Tuesday's education committee gives him the go-ahead to hold public consultations on "integrated" secondary provision in Stornoway.
"The school rolls are such that a merger would have no effect on the general teaching staff," Mr Galbraith said. "There would, however, be implications for senior management who would be eligible to apply for posts in the new school."
It was the merger issue that precipitated the resignation of seven parent and co-opted school board members, following heated exchanges at a meeting last week. Andrew Mackenzie, the board's chairman, told The TES Scotland that the verbal abuse they endured at the hands of senior staff was "the last straw". Board members had been treated with contempt, he said.
Alan Fraser, the depute rector, and Rodney Mackenzie, an assistant head, were said to have been particularly critical. The board says it was accused of having "failed in its duty to protect the school from outside forces in the past".
Andrew Mackenzie, who works for Brian Stewart, the council's chief executive, said: "As a parent body, we are independent. Yet we were being told what to think, what to say, how to behave. We were not prepared to compromise our position."
But at least one union leader described the board's action as "nothing short of childish". Bob Christie, Scottish secretary of the Professional Association of Teachers, said: "Surely the adult way forward would have been to sit down, discuss the criticisms and, if they are justified, resolve them."
The latest moves have left Nicolson staff feeling particularly aggrieved and frustrated because they are barred from public comment. "This injustice continues to be perpetrated," Mr Christie said. "Neil Galbraith, Brian Stewart and Andrew Mackenzie can all say what they like, traducing the staff in the process, but the staff are gagged. Glasnost has yet to hit the Western Isles Council."
The Nicolson's perception that the authority failed to defend it during last year's allegations of bullying still rankles. "There was not one iota of evidence that the girl who died was bullied here," one teacher said. "That should have been refuted by the education department and it wasn't because the staff were prevented from speaking out."
Mr Stewart has also been criticised for announcing he was writing to the rector "asking what action he intends to take with regard to the behaviour of some of his staff who would appear to be responsible for the entire school board resigning".
The chief executive's statement then added a glowing tribute to the "value" and "contribution" of the board, which was backed by Roderick Macdonald, the education committee's chairman.
One teacher commented: "Once again we have justice demanded before the facts are established."
The Nicolson staff's sense of isolation was further reinforced when Norman Macdonald, a Stornoway councillor, said he had received "numerous" telephone calls from worried parents appalled at the way the school board was treated. Mr Macdonald said parents were aware of the quality of the work put in by the majority of teachers but feel "there is a lack of management which will have to be rectified".
Andrew Mackenzie also pointed to weaknesses in development planning and quality assurance which made it difficult for the board to work with the school.
An HMI investigation, ordered by the Scottish Office last year, was also critical of management weaknesses at the school and highlighted "a climate of distrust and suspicion" between the school and the authority.
HMI's report led to the establishment of a working group under the chairmanship of the council's chief executive, which was aimed at resolving the tensions. Mr Galbraith was to be assisted in polishing his "management style" while Donald Macdonald, the rector, was effectively put on probation pending an improvement in his performance. Mr Macdonald had previously been carpeted for making "unauthorised statements" to the media.
A follow-up visit by HMI is scheduled for Tuesday and Wednesday next week.