Austria confirmed Monday that the presidential run-off election between Green-affiliated Alexander Van der Bellen and his far-right opponent Norbert Hofer is to be postponed until December 4.
Originally set for October 2, the vote was postponed due to problems with the glue on postal vote envelopes, Interior Minister Wolfgang Sobotka announced earlier in the day.
Sobotka had ordered an investigation into the problems with sticking strips after it emerged that some of them had been coming unstuck, potentially invalidating thousands of ballots.
Austrians have already been waiting five months for a new president after a May result was annulled. The country's Constitutional Court ruled that ballots and voting results had been handled improperly.
Economics professor Van der Bellen stated that he regretted the postponement, but took it in stride. "This glue mistake has shown us one thing: We need cohesion. More than ever," he said.
Meanwhile the Freedom Party (FPOe) of Van der Bellen's rival Hofer criticized the postponement sharply.
"The government is not in the position to ensure a proper punctual election. The embarrassments have no end," said FPOe General Secretary Herbert Kickl.
According to the Interior Ministry, there had never been a problem with the private printers that produced the envelopes before.
The government intends to file a claim for compensation against the private firm, which the ministry said had been used for previous national and state elections. A state printer will be tasked to produce the new envelopes.
Every vote counts in the repeat poll, with Van der Bellen having won the cancelled May run-off by a margin of 0.6 percentage points, prompting Norbert Hofer to cry foul.
Some 880,000 people cast postal ballots in the vote in May.