A group of nurses and union delegates are accusing the union of anti-democratic behaviour in a public letter they've put out today.
The letter signed by about 70 Nurses Organisation (NZNO) members said the union's board was wrong in trying to oust union president Grant Brookes.
Mr Brookes was in a dispute with a union organiser last year during fraught negotiations with health boards.
This led to an employment investigation that faulted his conduct.
The board meets in mid-September to vote on ousting him.
The letter said this was a rearguard action by members of the outgoing board and management who had eroded freedom of expression and nurses' input to the union.
"On many occasions, Brookes has found himself targeted by some members of the outgoing board ... who clearly prefer that the union is run by a tiny group of people without any input from members," the letter said.
NZNO kaiwhakahaere, or director, Kerri Nuku said the letter was one-sided and members should wait until they received more information in the next fortnight.
"It certainly does seem to be pre-emptive," she said.
"We've said just wait till all the information is available for every member to make an informed decision understanding both sides of the fence."
The accusation of being undemocratic did not stack up with her experience working closely alongside Mr Brookes, she added.
"We've done our utmost to ensure that democracy is upheld through this process and through all processes within the organisation, so I would refute those allegations," she said.
The letter claimed the management had aimed for smaller wage increases than they should and tried to muzzle those, like Mr Brookes, who tried to push for more.