Cornwall Council chief Alec Robertson faces a backbench rebellion and potential leadership challenge from members angry at plans to privatise council services.
More than a third of the authority's 123 councillors have forced a vote of no confidence in Mr Robertson which could see the controversial leader ousted at an extraordinary meeting next month.
A cross-party coalition of opponents has submitted 42 signatures, one more than the 41 required, to force a motion "to remove the leader from office".
The decision by the cabinet this month to press ahead with a so-called "shared services" proposals despite a vote against the plans by full council has forced the move.
Liberal Democrat deputy leader Alex Folkes said recent concerns about the "anti-democratic nature of the administration" had persuaded him to join the rebels.
But he claims the result is not a "foregone conclusion" and wants Mr Robertson to say "how he intends to lead in the future" at the meeting on October 16.
Andrew Wallis, Independent councillor for Porthleven and Helston South, said the leader was "not listening to the elected members". He added: "The direction he is taking this council is not in the best interests of Cornwall."
Mr Robertson described the motion as a "personal insult" but said he had developed a "thick skin".
He told the Western Morning News he had no intention of stepping down as leader, nor reversing the shared services decision, and warned that abandoning the privatisation plans would lead to "mass redundancies".
"I was appointed by the council to do a job and my administration has been phenomenally successful," he added. "I have operated a fully inclusive and open decision-making cabinet and will continue in my role until I am relieved of it."
Independent councillor for Redruth North, Lisa Dolley, claims she has suffered bullying since quitting the Independent group and signing the petition calling for a vote of no confidence.
She claims to have been stripped of her position as council design champion and removed from a board at Coastline Housing Association.
"I didn't want to be tarnished with the Tory brush – I like to follow my morals and principles," she said.
"I am nobody's puppet and don't like to be told what to do."