A pro-European Union candidate eked out a victory on Monday over a right-wing, anti-migrant rival to become Austria's next president, in a tight contest viewed Europe-wide as a proxy fight pitting the continent's political center against its growingly strong populist and anti-establishment movements.

European mainstream parties joined Austrian supporters of Alexander Van der Bellen in congratulating him on his victory over Norbert Hofer. But with less than a percentage point separating the two, Hofer's Freedom Party and its allies across Europe also had reason to celebrate what they cast as a major political surge by one of their own.

Hofer had been narrowly ahead of Van der Bellen, a Greens politician running as an independent, after the counting of votes directly cast on Sunday. But around 700,000 absentee ballots still remained to be tallied on Monday, and those numbers swung the victory to Van der Bellen.

Van der Bellen collected 50.3 percent of the votes compared with 49.7 percent for Hofer. Only a little more than 31,000 votes separated the two, out of more than 4.6 million ballots cast.

The results diminish the scenario that Austria's political landscape could immediately move away from its centrist political image through a new president who could oppose the government's EU-friendly policies and increase pressure for tighter migrant controls.

Still, the narrow margin for Van der Bellen is the latest indication that Europe's anti-establishment parties are gaining influence.