Austria's far-right Freedom Party has challenged the presidential election that its candidate Norbert Hofer lost by a narrow margin, the Constitutional Court said Wednesday in Vienna.
Green candidate Alexander Van der Bellen won with a lead of less than one percentage point - 30,836 individual votes - at the May election.
The Freedom Party has said it has found a number of irregularities in voting procedures, especially regarding absentee ballots.
The Constitutional Court aims to issue a ruling by July 8, when Van der Bellen is set succeed incumbent Heinz Fischer, a court spokesman said.
The court can order a new election in affected voting districts if it finds that there were unlawful practices and that these affected the overall outcome of the election.