Austria’s main centre-left opposition party on Monday reversed the result of its weekend leadership election, announcing that a computer error led to the wrong candidate being declared the winner.

Andreas Babler, the mayor of the town of Traiskirchen, outside Vienna, becomes the Social Democrats’ new leader as the party tries to turn around its fortunes ahead of a national election expected next year.

At a party convention on Saturday, Hans Peter Doskozil – the governor of the south-eastern Burgenland province and a figure better known to the public – had narrowly been declared the winner.

At a hastily called news conference on Monday, the head of the party’s electoral commission, Michaela Grubesa, announced that it was in fact Mr Babler who won, taking 317 votes to Mr Doskozil’s 280, the Austria Press Agency reported.

Ms Grubesa said that a recount had taken place on Monday because one vote was missing from the original total.

In the process, party officials discovered that “the result was reversed” on Saturday due to an error that occurred when votes were put into a spreadsheet, she said.

Ms Grubesa apologised to Mr Doskozil and argued that the party does not need to hold a new convention to ratify the result.

Mr Babler said he would ask for the votes to be checked again. “It’s really important that there are no question marks left, so that we can move forward with certainty,” he was quoted saying by the daily newspaper, Kurier.

The 50-year-old apologised for the impression his party had left in recent weeks and pledged to work on a “complete comeback of social democracy”.

Mr Babler is to the left of Mr Doskozil on issues including migration. Traiskirchen, where he serves as mayor, is home to the biggest refugee reception centre in Austria.

The Social Democrats have led many of Austria’s post-Second World War administrations but last served in government in 2017.

In Austria’s last parliamentary election in 2019, it won 21.2% of the vote – far behind the conservative Austrian People’s Party, which currently governs in a coalition with the environmentalist Greens.

They are currently polling in second place behind the far-right Freedom Party, which has benefited from voters’ frustration with rising inflation. The Freedom Party has used its signature hardline rhetoric on immigration issues to gain support in recent months.

The party’s leadership election came after discontent mounted with its previous leader, Pamela Rendi-Wagner, who was assailed for a perceived lack of vision and for an inability to translate public dissatisfaction with the government into more support.

Rivals parties mocked the Social Democrats’ spreadsheet hiccup.

“Those who can’t organise an election won’t win any either,” Douglas Hoyos, a member of the centrist NEOS party, wrote on Twitter.