The IFA has written to the acting Taoiseach expressing concerns about the impact of Mercosur on the Irish beef sector.
The IFA has urged Enda Kenny to contact the EU Commission President Jean-Claude Juncker asking that the latest agricultural negotiations do not proceed any further.
The EU and Mercosur negotiators are due to meet again in Brussels on Friday, amid an imminent exchange of offers between both sides.
The IFA National Chairman Jer Bergin has said a Mercosur trade deal would be “unequivocally negative for Irish and European agriculture” and would particularly damage Ireland's important beef sector”.
“The abolition of milk quotas last year has resulted in the expansion of the EU dairy herd, which is posing additional challenges for the beef sector,” said Bergin.
“Previous analysis by the European Commission has shown that a Mercosur deal would inflict losses of €7.8bn on the EU agriculture sector.
“Production standards in South American countries, such as Brazil, fail to meet EU standards on the key issues of traceability, animal health and welfare controls, the ban on hormone growth promoters and environmental controls.”