Janković had already offered to the party council on Wednesday to vote on his position in the party after the Corruption Prevention Commission released a report finding that he failed to account assets in the amount of at least EUR 2.4m between 2005 and 2012, but members of the council established there was no need for a vote.

The anti-graft watchdog's report has raised a major controversy in the country, especially as it also incriminated PM Janez Janša. It provoked calls for the resignation of both compromised politicians, and indignation after both won support from their respective parties.

Ahead of the congress, Janković rejected the report's findings in a public letter, arguing that he had never gained a single euro unlawfully and that his resignation would have been understood as admission of guilt by most people.

Due to the compromising report, attendance at the congress has been cancelled by the leader of the Socialists and Democrats (S&D) in the European Parliament Hannes Swoboda, especially after an invitation was declined by Igor Lukšič, leader of the opposition Social Democrats (SD), who cited previously agreed engagements.

The congress is expected to adopt a document called the "Founding Charter of Positive Slovenia - Slovenia 2020" and minor changes to the party statute.

The manifesto identifies solidarity, fairness and social equality as the party's fundamental values, while it also mentions worker participation as one of the ways to increase added value in the economy.