A woman walks by an election campaign poster of the presidential candidate Alexander Van der Bellen. Van der Bellen hoped the re-run would still take place sometime this year | Joe Klamar/AFP via Getty Images Rerun of Austria’s presidential vote to be postponed Candidates say balloting unlikely on October 2 because of problem with envelope glue.

A rerun of Austria's presidential election set for next month will be postponed on technical grounds, according to recent statements from the two candidates.

"I do not believe that the schedule can be kept," said the Green candidate Alexander Van der Bellen, who narrowly won the vote in May. He said he hoped the rerun can still take place sometime this year.

The reasons for postponement are faulty glue strips on postal voting cards, which cause the cards to break open after they had been sealed, making the ballot invalid.

Austria's Interior Minister Wolfgang Sobotka attributed the problem to a "production fault." Sobotka already said on Friday that he was considering postponing the vote.

Van der Bellen's rival, Norbert Hofer of the far-right FPÖ party, also expressed doubts voting can take place on October 2. In a video, posted on his Facebook page he said a new date had already been picked "because the organization has failed again because the Republic is not able to carry out elections properly."

Hofer didn't say what the new date was, however, nor did he say who had picked it since the official announcement of the postponement has yet to be made. Sobotka, the interior minister, said he would make a statement on this issue on Monday.