DEPUTY council leader Jim Currie spectacularly resigned from the Cabinet this week over his objection to the plan to hand services to a private company.
The Conservative had been tipped to stand as leader should Alec Robertson lose a vote of no confidence as leader of Cornwall Council on Tuesday.
But Mr Currie would not be drawn on whether he would do so after giving up his position as deputy leader of the council and member in charge of finance and corporate resources.
Already an outspoken critic of the plans, his resignation e-mail to Mr Robertson on Tuesday, copied to all other members and seen by the Cornish Guardian, said: "I feel I have pushed the cause of retaining council control over the joint ventures as far as I can with the Cabinet.
"The financial risks involved with the rush into the joint venture (JV) proposals are unacceptable. The JV is basically too large to control.
"We have wasted £42m+ on the unitary (authority), £42m+ on the incinerator and we are now proposing to risk a great deal more on the joint venture.
"I welcome your somewhat ambiguous offer to respect full council decisions on October 23 but I know you will never let go.
"I could not leave local government with billions of pounds of Cornish taxpayers' money at risk and on my conscience.
"Alec, this matter has never been personal."
He told the Cornish Guardian: "Honestly, I have done everything I can do.
"I have been out on a limb for a very long time and will just have to let the thing take its course and it's down to the membership and that's what the council is supposed to be about.
"It's absolutely the courage of my convictions and nothing else.
"The amazing thing is how many other people on the council think the same way across all parties. It's tremendously non-political."
The vote of no confidence was triggered by Mr Robertson's decision to press ahead with plans to privatise services despite a council vote against it.
Mr Robertson said this week that if he had a straight choice between staying as leader, or the shared services project going forward, he would choose the latter.
He added: "It's not that simple, of course, because I head the administration and, ironically, if I go it is most likely that I would be replaced by a leader who is against the JV and he would have to have a new Cabinet – he or she – that is against the JV as well.
"But it's not about keeping me in a job, or in a role at all. I didn't ask for this role, it is demanding, it is pretty thankless, it is a great privilege, of course, and I will do it until I am relieved of that responsibility, but I am not fighting to stay there. I am fighting to keep jobs in Cornwall and keep services.