An opponent of Fonterra's Trading Among Farmers plan says an attempt to reduce the size of outside investment does little to address fears farmers may lose control of the co-operative.
TAF would allow farmers to buy and sell shares among themselves.
It also includes a shareholders fund which would allow outside investors to buy the dividend rights of farmers' shares, without having voting powers.
Under the revised proposal that 10,500 farmer-owners will vote on later this month, Fonterra says the investment fund will be limited to up to 20% of its equity. That compares with the previous 25% ceiling.
Fonterra wants to let farmers trade their shares amongst themselves in a private market, while also setting up a $500 million fund to tap outside investment, to help bolster its financial position.
But Rotorua farmer Lachlan Mackenzie says he's not convinced the changes are enough to guarantee control remains in farmer hands.
He says the outside investors which get 20% of the equity will form a block and try and shift the cost centre to make sure the milk price goes down and effectively the dividend goes up.
"As soon as you get that you have a lack of unity within the cooperative, you have farmers fighting farmers, you have outside investors trying to have influence upon our cooperative".
"There is no agricultural cooperative anywhere in the world that has introduced outside equity into the cooperative that has maintained its focus on its core purpose of benefiting its supplying shareholders", says Mr Mackenzie.
When farmers voted on this issue two years ago, almost 90% of the 79% of them who voted backed it.
And the Fonterra Shareholders Council is supportive of TAF, but only after previous chairman Simon Couper stepped down after expressing concerns.
Southland farmer Grant Rowan says TAF is needed to protect Fonterra's future and the small changes that have been made are positive in terms of farmer control.
He says a strong, healthy, intergenerational cooperative is needed and the proposal delivers that as best it can.