Ursula von der Leyen was supposed to sign the European Union’s largest free-trade agreement on Saturday, proving the bloc’s standing as a geoeconomic force.

Instead, the European Commission president will have to figure out a way to salvage the Mercosur pact by rallying last-minute support from countries including Italy that helped delay the deal — yet again — over concerns it would hurt domestic farming sectors.

Negotiations on the trade accord — with Argentina, Brazil, Uruguay and Paraguay — have been drawn out over 25 years, rankling the South American countries. Brazilian President Luiz Inacio Lula da Silva said last week the time was now or never.