The deal is being pushed by Brussels chief Jean-Claude Juncker has vowed to “do everything we can” to seal an accord with the Mercosur trading bloc this year.
Mr Juncker insists the deal with Brazil, Argentina, Uruguay and Paraguay would show Europe was “open for business” and stabilise an international trading order rocled by the election of US President Donald Trump last year.
He said it would open up a vast new market for European vehicles and industrial goods, access to public procurement contracts and better protection of intellectual property rights.
But European famers fear any benefits would come at their expense, given the exporting prowess of the agricultural industries of Brazil and Argentina, by far the two biggest economies in Mercosur.
France and Ireland have both expressed concern that the deal could hit their lucrative beef exports and several central and eastern European countries are worried about the impact of a deal on ethanol production from crops.
Poland, Slovakia, Czech Republic, Austria, Hungary, Romania and Bulgaria all produce ethanol to various extents.
Copa-Cogeca, a lobby group representing EU farmers, said it rejected either beef or ethanol’s inclusion in the EU’s offer.
It said: “It would devastate the EU beef sector, growth and jobs in rural areas and undermine EU food safety standards.
“It is unacceptable that the commission is sacrificing the EU agriculture sector and allowing double standards on the single market.”
The Mercosur talks retain plenty of allies among EU states. Germany, Italy, Spain, the Netherlands, Portugal, the Czech Republic, Sweden and Denmark all back Brussels’s ambition for a year-end deal.
But the coming weeks will be a political test of how far the EU is prepared to go to secure an agreement.
EU trade commissioner Cecilia Malmström said: “We are talking about a huge market that has traditionally been closed. There is a lot to gain.”
But she admitted there was “still work to do” and acknowledged concerns raised by European producers.
She said: “We cannot conclude it until we feel that we can solidly answer all of the questions that member states will put to us.”