The United Dairyfarmers of Victoria wants new Chain of Responsibility laws scrapped, just weeks after they were approved.
Amendments to the Heavy Vehicle National Law, which are due to take effect in mid-2018, mean farmers could be held responsible for the safety of heavy vehicles that enter their farms even after they have departed their property.
Friday's UDV conference carried a resolution to "strenuously oppose" the changes, except where the dairy farmer was responsible for loading or restraining of a load.
President of the UDV's West Goulburn branch Wade Northausen said the new law was a disaster.
"For anyone who wants to look into it, this is an absolute catastrophe," he said.
"The fines for one person to break these rules is $300,000 and for a corporate, it is $3 million."
Mr Northausen said farmers should not be held accountable for things that were the responsibility of other people running their own businesses.
"The terminology is so broad at the minute that you have no idea what your obligations are," he said.
He called on the UDV and the Victorian Farmers Federation to do "whatever it takes" to lobby to get rid of the changes.
Earlier VFF president David Jochinke said it was unclear exactly what farmers' obligations were under the new laws.
Agriculture was not yet ready for the laws.
"So I have been working with Tasmania, who are the other people who have raised major concerns with this, (to say) if you can't make the definition clear, they should delay the enforcement of what we are required to do," he said.
"Because we don't know if somebody is tired, we don't know if somebody's truck is roadworthy, we don't even know if the truck has got the right gauges on the airbags, if it is overloaded or not.
"Are there five questions we need to ask, two questions we need to ask, ... that actually cover off - tick - that we have done our part of the chain of responsibility."
But Cobram East dairy farmer and West Goulburn UDV branch member Paul Mundy said the VFF should be "absolutely demanding that we as primary producers cannot be put in that position, full stop.
"Not whether we answer two or three questions, that's bull---t. We have no ability to be able to enforce that and who says the driver is indicating the truth or not; they may not even know themselves."
Mr Jochinke said turning back the clock to advocate against the laws could be a position but "the reality is that it is law now. It is how we execute within the legal framework, that is for us the question".
Stanhope dairy farmer Alison Couston, from the UDV's West Goulburn branch, in moving the resolution said it should be the responsibility of those who transport goods to run their own businesses safely.
"At the moment we are being told there is not much to do, but we will be required to keep more and more records and take more and more responsibility, as has happened in so many other areas," she said.
Colac dairy farmer Stewart Carson said farmers were "the soft target in all of this".
"I believe if someone was to have a load of cattle come through from NSW or wherever, under the law, as is stands ... when that truck comes onto our property, if it is unroadworthy or the driver has exceeded his hours of driving etc, that we become responsible," he said.
"To me, we cannot accept those sorts of conditions, those must remain with the people responsible for the transport.
"We on our farms and certainly in our own trucks and the like are responsible - we need to take care of that.
"But if I started climbing over a transport that arrived at home and said it's unroadworthy, I believe that one, I am not qualified to do that, and two, I might get my lights punched out.
"So I think this is unrealistic and we need to strenuously oppose it."
But UDV vice president Longwarry dairy farmer John Versteden said farmers needed to accept some responsibility in this space.
"I think with this stuff, and I could be wrong, but if you've got silage coming off and rain's threatening and the silage contractor tells you my men are tired, they need to stop now and you say no you need to keep going you need to beat the rain - this could have implications," he said.
"You need to open your mind a little bit."
Mr Versteden said the issue clearly was across most commodities, so should be referred through to the VFF.
Mr Northausen, from the West Goulburn branch, acknowledged it was a cross-commodity issue.
"But we've brought it up at UDV because we could get it on the books now," he said.
"At the end of the day, it is completely unacceptable to have this as law.”