The Italian Senate will on Wednesday decide whether to allow the commencement of a criminal case against Matteo Salvini, the far-right leader accused of kidnapping 131 migrants last year when as interior minister he prevented them from disembarking a coastguard ship.

This is only the most recent legal trouble for Italy’s most powerful populist. In less than two years he has been placed under investigation five times, is the subject of one ongoing trial, and been named in dozens of lawsuits for defamation and instigation of hatred.

If found guilty in all the various lawsuits, Salvini could face prison and be forced to pay thousands of euros in fines. Only since media mogul Silvio Berlusconi, who was convicted in one out of 32 court cases and sentenced to four years in prison, has Italy seen a political leader implicated in such a long list of judicial proceedings.

“Whereas Berlusconi’s legal troubles have their own Wikipedia page, and were primarily connected to his private life, Salvini’s are solely the result of his political activity,” says Matteo Pucciarelli, journalist at newspaper La Repubblica and author of Anatomy of a Populist: The True Story of Matteo Salvini.

Salvini seems determined to embrace the trials against him and initially instructed his League party to vote in favour of proceeding with the court case, with the clear intention to use it as a political weapon, before shifting to abstain.

His political opponents – the Democratic party and the Five Star Movement (M5S) – will back a trial but were circumspect enough to ask to postpone the senate vote until after regional elections were held in Emilia-Romagna in order to prevent Salvini from exploiting the court case to his own advantage during the campaign.

A hard line on immigration was Salvini’s signature issue as interior minister, his role from June 2018 to September 2019. One of his first moves in office was to declare Italian ports closed to rescue ships engaged in saving migrants fleeing Libya. There were subsequently 25 standoffs between rescue vessels and Italian authorities, some of which became the focus of investigations as prosecutors accused Salvini of the illegal detention of migrants.

At least three investigations against Salvini concern the alleged kidnapping of asylum seekers:

A criminal case for refusing to allow 177 migrants to disembark from the coast guard ship Ubaldo Diciotti, which was blocked by the senate in March 2019. At the time, Salvini could count on the support of his coalition partner, the anti-establishment M5S.

Allegedly depriving more than 100 migrants on board the Gregoretti coastguard ship of their liberty by failing to allow them to disembark. On Wednesday the senate will vote whether to lift his immunity and authorise the trial in Catania, Sicily. If convicted, he could face up to 15 years in prison.

On 27 February, the Senate immunity panel will vote on whether he should face trial for allegedly kidnapping another 161 migrants on board the NGO rescue ship Open Arms.

In response to these accusations, Salvini has said that for him these proceedings are “medals for having defended Italy’s borders”. He denies allegations of kidnapping, adding: “If I’m a kidnapper I will face the consequences. I just did what the Italian people asked me to do.”

“We are talking about judicial proceedings which are the result of the way this political leader manages his power,” said Alessandro Gamberini, a lawyer for NGOs Proactiva Open Arms and SeaWatch.

Salvini is also currently the subject of a trial in Turin for contempt, following his description at a 2016 rally of the Italian judiciary as “a cancer to eradicate”. He has pleaded not guilty but is yet to attend a hearing, saying he was busy with his work as a senator.

His campaign against pro-migrant NGOs has also brought judicial consequences.

The Milan prosecutor’s office in September placed Salvini under investigation on suspicion of defaming Carola Rackete, the German captain of the migrant rescue ship Sea-Watch3. In the suit, which mentioned rape threats against Rackete on social media, the 31-year-old captain argued that Salvini, who called her a “rich Communist scamp who shops in Portofino”, spreads hatred and instigates people to commit crimes.

Salvini denies the allegations and in a statement on Twitter claimed the “German communist” had “asked the prosecutor’s office to shut down my Facebook and Twitter pages. There is no limit to the ridiculous. So, I’m only allowed to use Instagram???”

Yassin, a 17-year-old of Tunisian descent, meanwhile filed a defamation lawsuit in January against Salvini, after he allegedly accused him of drug dealing. Salvini rang the doorbell of the Bologna home where the boy lives with his family in front of TV cameras while campaigning in Emilia-Romagna and asked: “Is it true you’re a drug dealer, as your neighbours are saying?” He later told the TV channel Rai he did not regret the incident and it was necessary to fight “drug dealing doorbell-to-doorbell.” He is contesting the case.

“This is just an example of how people are used unscrupulously in his electoral campaign,” said Yassin’s defence lawyer, Cathy La Torre. “I am following more cases of ordinary citizens who were used by Salvini as electoral weapons.”