Supporters of opposition leader Janez Janša gathered in front of the Celje court building where he is standing trial for a second time to protest against what they call an "injustice system"

The rally on 12 December follows the first such on 26 November, which Janša described as the "beginning of a rebellion against the injustice system" that will "last as long as necessary."

Janša has stood trial several times on various charges, and both him and his supporters have been arguing that he is a victim of a justice system being abused by his political opponents.

In the most infamous case, Janša was sentenced to two years in prison before the 2014 general election for allegedly accepting a promise of a bribe in connection with the 2006 tender won by the Finnish defence contractor Patria when he served as prime minister.

He was released after six months on order from the Constitutional Court, which later quashed the original ruling and ordered a retrial, but the case became statute-barred in 2015.

Janša has also been tried for insulting journalists, and a former director of the Slovenian Press Agency, while in the case at the Celje court he is accused of corruption regarding transactions twenty years ago involving a piece of land in the Trenta Valley he once owned.

Following the first rally in Celje, where Janša suggested the Slovenian "injustice system" was worse than mafia, representatives of judges, the government and ruling coalition parties decried what they described as attempts to undermine the judiciary.

The rally, which followed hateful social media posts targeting judges involved in the Patria case, was condemned in the strongest terms by the parliamentary Justice Committee at a dedicated session, but Janša remained defiant, announcing the next rally for 12 December.

Addressing the latest rally, Janša criticised the proceedings against him and the government, comparing the gathering to the mass protests in Ljubljana in 1988 against a military show trial of Janša and three other defendants that galvanised the movement that led to Slovenia's independence.

He described the current government as a puppet government, where the country was in fact controlled by "criminals who get to have €30 million debt written off, by nightclub hostesses and godfathers of UDBA mafia" who are "untouchable, thanks to a well-placed, corrupt group of prosecutors and judges".

"That is why we must head to the next election with our eyes open and en masse. Let us not fall for the Manchurian candidates of the left or the various Freemasons," he said of new faces that tend to win elections in Slovenia.

He argued the large number of people gathered showed the "era of the dominant media is slowly coming to an end", a reference to media affiliated with his Democratic Party (SDS).