Moldova’s crucial referendum on joining the European Union is too close to call, partial results showed Monday, as President Maia Sandu condemned an “unprecedented assault” on the country’s democracy.

Moldova voted in favor of adding a path to the European Union to its constitution, and gave the incumbent president the most votes in elections Sunday, but neither result was the win leaders wanted.

Electoral data shows that Moldovans have voted by a razor-thin majority in favor of securing the country’s path toward European Union membership.