Austria could hold a referendum to leave the European Union under certain conditions, according to the far-right presidential candidate Norbert Hofer, who lost the vote in May but has been given a chance for a re-run.

Hofer, a candidate of far-right, anti-immigration Freedom Party, said in an interview with Italian newspaper Corriere della Sera on Saturday that holding a referendum on leaving the bloc would be imperative if Turkey were to join the bloc, or if European treaties were changed towards further increasing of the decision-making powers of Brussels at the expense of member states’ national governments.

Hofer spoke a day after Austria’s Constitutional Court announced it annulled the results of the second round of the presidential elections, citing irregularities in counting the ballots, and ordered a re-run.

The far-right candidate lost by a slim margin of just over 30,000 votes, equivalent to less than one percentage point, to the former Greens leader Alexander Van der Bellen in the May 22 run-off.

The court ruling gives Hover a second shot at winning the vote for president. In Austria, the position of head of state is largely ceremonial but a victory by the far-right would be loaded with huge symbolic significance ahead of the next general election in 2018. In addition, a victory for Hofer could further boost support for other populist parties elsewhere in Europe.

Hofer’s comments reiterated his earlier warning Austria could hold a referendum on whether to leave the EU in case of ‘centralisation’ by Brussels.

"If a course is set within a year further towards centralization instead of taking (the EU's) core values into account, then we must ask Austrians whether they want to be members," Reuters quoted Hofer as saying in an interview with Oesterreich newspaper last week.