Around 1,500 French farmers protested outside European Parliament in Strasbourg on Friday.
The demonstrators, many driving tractors, are angry over EU proposals that they say threaten their livelihood.
Negotiations over the Common Agricultural Policy are still going on in Brussels.
The protesters claim the plans lean too far towards environmental issues that will make farming more expensive.
"The Common Agricultural Policy must help to sustain farmers on the land," explained Laurent Champenois of the French Farmers' Unions Federation. "There are only 500,000 farmers left, but the future reform proposed to us will reduce the number of farmers, it will cut it by half."
The farmers are particularly against "eco-schemes" that grant bonuses to those who participate in environmental programmes that would be mandatory under the new rules.
Sector representatives claim the policies risk reducing aid by a third to more than half of France's grain producers.
The latest changes will come into effect in 2023.