Austria’s Constitutional Court has annulled the results of the second round of the presidential elections, citing irregularities in counting the ballots.

Norbert Hofer, a candidate of far-right, anti-immigration Freedom Party, 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.

Postal ballots had tipped the balance in Van der Bellen’s favour.

The Freedom Party had challenged the result, saying that thousands of postal votes had been opened earlier than permitted under election rules and some had been counted by people unauthorised to do so.

The Constitutional Court ruled on Friday that there were official grounds to invalidate the vote in the interests of the public and democracy.

The results have deprived the Freedom Party of a victory that would have been a decisive boost for far-right parties elsewhere in Europe, the BBC commented in its coverage of the news.

With the result of the run-off vote declared invalid, Hofer will now have another chance to become the first far-right head of state in the European Union.

While the Freedom Party doesn’t want Austria to follow Britain out of the EU, it is calling for radical reform of the bloc and has threatened to hold a referendum for leaving the union if it doesn't get its way. 

Interior minister Wolfgang Sobotka said that a date for the re-run of the election would be announced next week. The re-run vote is not expected to take place before September or October.