Health Services Union (HSU) acting national president Chris Brown is taking steps to remove national secretary Kathy Jackson from her position.
Mr Brown announced on Monday he would be charging Ms Jackson under the union's registered rules.
He said the 10 charges would cover "gross misconduct, gross neglect of duty and substantial breach of the rules and be seeking her removal from office".
On Friday, Ms Jackson said she would not be resigning, despite moves to force her out.
Over the past few months, senior officials in the troubled union have repeatedly suggested she voluntarily step down.
Ms Jackson - who helped blow the whistle on the misuse of union members' funds, leading to two Fair Work Australia (FWA) investigations - is the subject of several complaints.
"I did the right thing by blowing the whistle on massive corruption in the HSU," she said in a statement last week.
"I have told the truth at all times and I have done nothing wrong."
Mr Brown said the move to oust Ms Jackson was necessary to repair union members' confidence and pride in the organisation and its executive.
"We have been working hard over the past 12 months to repair the reputation of the HSU and to put in place measures that will prevent this from occurring again in the future," he said in a statement on Monday.
"However, in order for this to be successful, the HSU needs a national secretary who is dedicated to that cause, who will respect the will of the national executive and national council rather than working against it.
"We need someone who will put the interests of all members of the HSU ahead of their own interests and ambitions."
The charges against Ms Jackson will initially be investigated by the union's ombudsman, Errol Hodder, who will report to the national executive.
The executive will consider his report and Ms Jackson will have a right to appeal to the union's national council or take the matter to civil courts.
Ms Jackson told ABC Television the charges against her were "totally fabricated".
She accused Mr Brown of using the manoeuvre for his own purposes.
"He's been sitting on these charges since April. He's done nothing about it," she told ABC's 7.30 Report on Monday.
"He's waited until the nominations (for HSU elections) are about to open to use these against me to smear me once again."
