Around 1,000 farmers staged a protest at the constituency office of Minister for Agriculture Simon Coveney in Cork to protest at EU proposals to reform the Common Agricultural Policy.
The Irish Farmers' Association, which organised the demonstration, said farmers could lose up to 40% of their CAP payments.
However, Mr Coveney has rejected the figures put forward by the IFA.
The IFA is concerned that proposals by the European Commission to move to a system of flat-rate payments per hectare will cost 80,000 of the country's most productive farmers a combined €250m.
Farmers gathered at Mr Coveney's constituency office this afternoon in Carraigaline calling for him to take a tougher stance for Irish farmers in the negotiations.
Minister Coveney insists that while reform of CAP payments is inevitable, it will not lead to anything like the losses being predicted by the IFA, and the outcome will be fair for all Irish farmers.