The NFU says it will speak Thursday at agriculture committee hearings at the House of Commons on Bill C-18, the Agriculture Growth Act.
It says the bill would increase farmers' costs, reduce farmers' autonomy and compromise Canadian sovereignty.
At the same time, the NFU says the bill would provide more revenue and power to multinational agri-business corporations.
The NFU says some parts of the bill should be introduced separately to allow for proper debate but says the Plant Breeders Rights Act amendments should be tossed out completely.
Terry Boehm of the NFU says the amendments would have the effect of taking away a farmer's control of his seed.
"Canada does not have to pass Bill C-18 to comply with international trade rules," he said. "We can develop our own seed law system that works for farmers and which creates a strong foundation for the kind of food system that will truly support future generations."
The Canadian Federation of Agriculture has come out in support of the proposed changes to the plant breeders legislation, with president Ron Bonnett saying accessibility to research is incredibly important to keeping Canadian farmers on the forefront.
He said the new legislation strikes a good balance between giving developers the ability to see a return on their investment and research efforts, while also preserving the right for farmers to save and condition seed for their own use.
However, NFU president Jan Slomp said the bill further erodes the rights of farmers by reducing the transparency and public participation requirements for regulations.
"(It allows) companies to present foreign studies instead of Canadian science when seeking regulatory approvals under five agricultural Acts," said Slomp. "These changes reflect undue influence by corporate lobbyists and a federal government that is all too ready to help global agribusiness at the expense of Canadian farmers."
Slomp said the bill would change eligibility rules for the Advance Payments Program, making it possible for farmland investment corporations with as little as one-third Canadian ownership to take advantage of a loan program that was intended to help farmers deal with cash flow problems.