Greece will not sign off on the EU-Canada trade pact if it is not granted exclusive rights to use the term "feta" for the classic salty cheese it produces.
Greece objected to Canadian companies using the name feta for their own crumbly white cheeses, in a document prepared for an EU trade meeting on May 7.
Greece will challenge the text of the preliminary trade agreement, which would allow Canadian companies to continue using the feta name if they were doing so before October 2013, according to Reuters news agency.
"We have informed the European Commission about the numerous usurpers of our famous feta cheese in the Canadian market," the Greeks wrote, according to Reuters, adding that "it would be extremely difficult, if not impossible for us, to endorse" an EU-Canada trade deal without a change in the terms.
Canada and Europe reached an agreement on a wide-ranging free trade deal last year, following an intense period of negotiations. A Greek veto at this stage could further damage already frayed relations with its European neighbours, and potentially derail the entire deal.
Greece's left-wing government is struggling to reach a deal with its creditors over the terms of a financial bailout. The Greek government has yet to provide the list of detailed economic reforms that its creditors have demanded to see before they sign-off on the next tranche of the Greek bailout.
Greece says "feta" is part of its cultural heritage because the cheese has been made in Greece for 6,000 years. It wants Canadian rivals to name their own cheese as "feta-style".
The EU's system of protecting food names by geographical location has already proved controversial as the bloc seeks free trade deals across the globe, including a potential deal with the United States.
Both Canada and the US have complained that the EU system of protecting products is not fair because European immigrants in North America have produced similar products for generations.