CANBERRA — Former Australian prime minister Malcolm Turnbull is urging the Liberal Party to support a proposed free trade agreement with the European Union, as its Coalition partner, the Nationals, pushes to block the pact in Parliament. Australia’s Labor government says the agreement could boost the economy by A$10 billion a year. Trade negotiations have lasted a decade, and Trade Minister Don Farrell has argued the deal cannot be improved further. Turnbull called on Australia to “seize every opportunity to increase market access for Australian exporters.” His appeal puts pressure on Liberals to choose between the party’s free-trade tradition and growing opposition among farmers concerned about the agreement. Nationals leader Matt Canavan said Friday that both Coalition parties opposed the deal, even though neither the Liberal shadow cabinet nor the Coalition party room had yet debated the position. His declaration exposed a divide within the Liberals: pro-trade moderates aligned with business groups favor the agreement, while conservative MPs have backed the Nationals and their farming constituency. The dispute leaves the opposition’s position unsettled as the government seeks support for a pact reached after years of talks. For exporters, the central question is whether the agreement will open valuable new markets; for farmers, the political battle centers on whether its terms adequately protect their interests.