Notwithstanding the criticism, the strategy appears to have worked – Italians have applauded his crackdown on migrant arrivals and his promise to recruit more police.
Since last year’s general election, Mr Salvini has doubled the League’s support from 17% to 34%.
Alfonso Bonafede, the justice minister, downplayed the incident. “I don’t think Italians will be losing sleep over Salvini’s son having a ride on a police jet ski.”
On Wednesday, Mr Salvini said he would finally give permission for more than 110 migrants to disembark from an Italian coast guard ship that rescued them at sea at the weekend.
The vessel had been anchored in the Sicilian port of Augusta since Saturday.
There had been a stand-off over the fate of the asylum seekers, with the interior minister saying he would not let them step foot on dry land until other EU countries accepted them for settlement.
A deal has now been reached, he said, with the migrants to be accepted by Germany, Portugal, France, Ireland and Luxembourg.
“In the coming hours I will authorise the disembarking because we are sure that the migrants will not be a burden on Italian citizens,” he wrote on Facebook.
Mr Salvini’s refusal to accept more migrants in the last year has led to a dramatic drop in the numbers trying to cross the Mediterranean from Libya, where they spend months or even years in inhumane conditions.