Angry irrigation farmers are taking their concerns about the controversial Murray-Darling Basin Plan to the national capital.
More than 3000 people - some in trucks, tractors and utes - are expected to join the "Convoy to Canberra" on Monday and call for the plan to be paused and overhauled.
"Can the Plan" protesters are planning to meet in Yass before driving en masse into Canberra.
"We want a plan that works for our farmers, environment and communities," said rally co-organiser Darcy Hare.
"At the moment it is hurting all of these, and we have grave concerns for the future of Australia's food security.
"We get report after report, inquiry after inquiry, highlighting the flaws in the basin plan. Yet all we get from the Murray-Darling Basin Authority is denial, and all we get from Water Minister David Littleproud are his ridiculous calls to implement the plan 'in full and on time', despite admitting it has flaws."
The Murray-Darling Basin Plan became law in 2012 and governs water use across the basin's four states and the ACT.
Mr Hare said concern about the Murray-Darling Basin Plan and water issues was spreading.
"A rally in Melbourne 18 months ago had about 300 people there. In Tocumwal in September, there were 3000 or 4000 people," he said.
"The number of people who are getting their heads around how important this issue is for rural Australia is growing."
Convoy organisers were hoping to take their message to Prime Minister Scott Morrison personally, but have not yet been able to confirm whether he will meet with them.
"The great shame is that solutions exist which could provide us with a balanced Basin Plan that protects farmers, communities, the environment and food security. Unfortunately Mr Littleproud, as well as Environment Minister Sussan Ley, know these solutions need a tough approach that requires political courage, and at present it does not exist," Mr Hare said,
"We need to make Prime Minister Morrison aware of this indisputable fact.
"It's no secret agriculture is essential in this country.
"It provides our food security, jobs and is a catalyst for a healthy economy."
Shelley Scoullar, chairwoman of the Speak Up community group, said the rally was being supported "by a vast range of concerned farmers, business operators and community members".
"Our concerns are for the environmental damage which is occurring, while at the same time we are seeing destruction of our regional communities and food production. Our nation's food security is being threatened, yet we have a government in denial," Ms Scoullar said.