SABAUDIA, Italy — Like a nationalist gone wild, Matteo Salvini took off his shirt, picked up his mojito and partied with Spring Break abandon.

In the D.J. booth of the Papeete Beach club on the Adriatic coast, Mr. Salvini, Italy’s interior minister, spun Italian rap music and joked with his boys as strutting go-go dancers in skimpy leopard skin bathing suits solemnly put their hands on their hearts during the playing of the national anthem. He blew kisses as fans chanted his name as if it were the song of the summer.

For much of August, Mr. Salvini, 46, a populist Everyman with a talent for expressing Italy’s id, whether he’s scarfing down Nutella or locking out migrants, has moved the seat of Italian government to the beach chair. After weeks of a highly visible vacation in Milano Marittima, Mr. Salvini, was rested and ready to force a government crisis that could make him prime minister.

“Like in a marriage, when you spend more time arguing than getting along and making love, it’s better to look each other in the eye and make the choice that two adults should make,” Mr. Salvini said at a political rally in the beach town of Sabaudia Wednesday night, noting that, as a divorcee, he had experience in the subject.