Uruguay’s presidential candidates will go head to head in a runoff vote on Nov. 30 after failing to secure a majority needed to win the presidency on Sunday. The race is widely expected to be one of the narrowest Uruguay has seen in years, with the future of its marijuana legalization scheme hanging in the balance.

With around 90 percent of the ballots counted Monday, leftist candidate Tabaré Vázquez, a 74-year-old former president and chosen successor of current president José Mujica, garnered 46.5 percent of Sunday’s vote. Center-right challenger Lacalle Pou, 41, secured 31.1 percent, election officials said. A third candidate, Pedro Bordaberry, received around 13 percent of the vote in the first round.

Election observers had largely anticipated a runoff vote between Vázquez and Pou, and polls predict that Nov. 30 will see an extremely tight race. The leftist Broad Front coalition, the political party of President Mujica and Vázquez, is also facing a referendum after 10 years of dominance in Uruguay’s Congress. While the party ushered in a decade of stability and healthy economic growth with Mujica and Vázquez at the helm, voters have been disgruntled with high taxes, shortfalls in education reform and some of the social initiatives passed under Mujica’s term, including its historic law to legalize the cultivation, consumption and distribution of marijuana.

While Vázquez has endorsed the marijuana law, Pou has pledged to roll it back, allowing only for consumers to grow the plant at home for personal use but ending any state involvement in selling and distributing marijuana. Only around 30 percent of Uruguay’s population supports the law.

Third-place candidate Bordaberry threw his support behind Pou following Sunday’s vote. Three polling firms also predicted a win for Pou on Nov. 30, although analysts note that the Broad Front has been preparing for the runoff vote and will step up its campaign aggressively over the next several weeks.