Italy's former interior minister and far-right leader Matteo Salvini went on trial today for allegedly illegally blocking more than 100 migrants in dire sanitary conditions from disembarking from a rescue ship.

On the opening day of the trial in Palermo, Judge Roberto Murgia said all the witnesses submitted by the parties would be allowed to testify.

This includes US actor Richard Gere, who made a humanitarian visit to the ship, and Italy's former prime minister Giuseppe Conte.

Mr Salvini, the leader of the far-right League party who is known for an "Italians first" policy, is charged with kidnapping and abuse of office for using his position as interior minister to detain the 147 migrants at sea in August 2019.

The hearing was largely procedural and lasted less than three hours before Judge Murgia set the next hearing for 17 December.

Mr Salvini, who was present in court, could face a maximum of 15 years in prison if convicted.

"You tell me how serious a trial is where Richard Gere will come from Hollywood to testify about my nastiness," Mr Salvini told journalists outside the courtroom.

"I hope it lasts as short a time as possible because there are more important things to take care of."

Mr Salvini has said he was protecting Italy with his "closed ports" policy aimed at stopping people attempting the dangerous Mediterranean crossing.

He has claimed the decision not to allow the ship to dock was not his alone, but agreed by the government, including by then-prime minister Mr Conte.

Richard Gere at a press conference on the island of Lampedusa in August 2019

Other witnesses the court allowed to testify include Italy's current Interior Minister Luciana Lamorgese and Foreign Minister Luigi Di Maio.

Civil party Open Arms, the Spanish charity that operated the rescue vessel, had requested Mr Gere as a witness, since he had boarded the ship in solidarity with the migrants before it docked at the Sicilian island of Lampedusa.

Mr Salvini tweeted a photo of himself inside the courtroom, standing in front one of the cells used for some defendants.

"This is the courtroom of the Palermo prison. The trial wanted by the left and by the fans of illegal immigration begins: how much will it cost the Italian citizens?" he tweeted.

Outside the courtroom, the founder and director of the Spanish charity Open Arms that operated the rescue ship said the trial was not politically motivated.

"Saving people isn't a crime, but an obligation not only by captains but by the entire state," Oscar Camps told journalists.

The beginning of the trial came as 406 migrants rescued in various operations off the coast of Libya by the German charity ship Sea Watch 3 arrived at the Sicilian port of Pozzallo to be disembarked.

In the 2019 Open Arms case, migrants were finally allowed to leave the vessel after six days, following an order by the prosecutor's office. A subsequent onboard inspection revealed serious overcrowding and dire sanitary conditions.

Italy's Senate voted last year to strip Mr Salvini of his parliamentary immunity, paving the way for the trial.

A related case in which Mr Salvini, 48, was accused of blocking other migrants at sea on an Italian coastguard boat was thrown out by a court in Catania earlier this year.

Mr Salvini's party takes a hard line on migrants, arguing that Italy bears an unfair burden as the first point of entry into Europe for those arriving from northern Africa.

When he blocked the ships, Mr Salvini was part of a coalition government and held the positions of interior minister and deputy prime minister.