The knife-edge finish was a shock for supporters of Sandu who hoped the vote would deliver a firm message of intent to bring the poor ex-Soviet agricultural economy into the European Union by 2030 and leave Moscow's orbit for good.
But the result means a clause will be added to the constitution defining EU accession as a goal. Moldova began the long process of formal accession talks in June.
The people of Moldova have spoken: our EU future will now be anchored in the constitution. We fought fairly in an unfair fight—and we won.— Maia Sandu (@sandumaiamd) But the fight isn't over. We will keep pushing for peace, prosperity, and the freedom to build our own future.October 21, 2024
"The people of Moldova have spoken: our EU future will now be anchored in the constitution. We fought fairly in an unfair fight — and we won," the 52-year-old leader wrote on X.
At a presidential election held alongside the referendum, Sandu won 42 per cent, short of the 50 per cent needed to win outright and paving the way for a tightly-fought November 3 runoff against former prosecutor-general Alexandr Stoianoglo, who won 26 per cent.
Earlier, Sandu had told Moldovans there was "clear evidence" that criminal groups working with "foreign forces hostile to our national interests" had aimed to buy off 300,000 votes.
"Criminal groups... have attacked our country with tens of millions of euros, lies and propaganda, using the most disgraceful means to keep our citizens and our nation trapped in uncertainty and instability," she said.
In the runup to the vote, authorities said there had been Moscow-backed meddling attempts spearheaded by fugitive tycoon Ilan Shor, including an effort to buy up 130,000 people to vote "no" and support a specific candidate at the election. Shor denies wrongdoing.
The Kremlin, which denies interfering, denounced the votes in Moldova as "unfree", casting doubt on what it said was a "hard-to-explain" increase in votes in favour of Sandu and the EU, and challenging her to "present evidence" of meddling.
The EU defended Sandu, saying Moldova had faced "really unprecedented intimidation and foreign interference by Russia and its proxies ahead of this vote".
Ursula von der Leyen, president of the European Commission, hailed the outcome of the referendum in a post on X: "In the face of Russia's hybrid tactics, Moldova shows that it is independent, it is strong and it wants a European future!"
The Organization for Security and Co-operation in Europe (OSCE) said the voting campaigns had been marred by foreign interference and active disinformation efforts.
The future of the southeast European nation of under three million has been in the spotlight since Russia's invasion of neighbouring Ukraine at a time of mounting confrontation between Moscow and the West.
Ties with Moscow have deteriorated as Sandu condemned the Kremlin's invasion of Ukraine and diversified energy supplies away from Russia.
Moldova's twin votes came ahead of next Sunday's tightly-contested parliamentary election in Georgia, another former Soviet republic that aspires to join the EU but which Russia historically sees as part of its sphere of influence.
In a speech on Monday afternoon, Sandu said "there is still one more battle to fight", urging Moldovans to back her in the runoff of the presidential contest.
Stoianoglo, who is backed by the traditionally pro-Russian Party of Socialists, has said that, if elected, he will build a "balanced" foreign policy involving ties with the EU, the United States, Russia and China.
He boycotted Sunday's referendum, calling it a ruse to boost Sandu's re-election bid. He challenged Sandu to a televised debate ahead of the runoff.
