Italy's senate has lifted the parliamentary immunity of former interior minister Matteo Salvini, opening the way for him to face trial accused of illegally detaining migrants at sea last year.

The upper house voted along party lines and the result was widely expected.

The senate voted 149 to 141 to strip the right-wing leader of his immunity, with one abstention.

Mr Salvini could serve up to 15 years in prison if convicted of the kidnapping charges.

It is the second time he has lost parliamentary immunity over a migration charge this year.

"I am proud to have defended Italy. I would do it again and I will do it again, also because just this July the arrivals are six times those seen in the same period a year ago, with the League party in government," a defiant Mr Salvini told the senate after the vote.

The head of the anti-immigrant League party is already set to stand trial in a separate but similar case.

Prosecutors in the Sicilian city of Palermo accuse Mr Salvini of abusing his powers as then-interior minister in August 2019 to illegally prevent more than 80 migrants, rescued in the Mediterranean Sea, from disembarking the Open Arms charity ship.

Ministers cannot be tried for actions taken while in office unless their parliamentary immunity is revoked by the senate.

Mr Salvini has insisted the decision to stop the migrants from getting off the ship until a deal was brokered with European Union countries to take them in was reached collectively within the government.

That is the same defence Mr Salvini is using for the other trial, in which he is accused of blocking migrants from disembarking from the Italian Gregoretti coast guard boat last July.

In February, the senate voted to strip him of his parliamentary immunity in that case.

The preliminary hearing has been postponed three times due to the coronavirus pandemic, and is now scheduled to take place in Sicily on 3 October.