Italy’s leading political powers may not have Giuseppe Conte to push around anymore.

That was the message Mr. Conte, Italy’s prime minister, sent Monday as he delivered an ultimatum to the populist government’s warring coalition partners.

In a remarkable prime time news conference, he told them that if they didn’t stop paralyzing the government, and derailing sensitive financial negotiations with the European Union, with their perpetual bickering, political point scoring and media propaganda, he would walk and bring the government down with him.

“I’m not here just to scrape by or drift,” Mr. Conte said, demanding a “clear and unequivocal choice” from the coalition partners as to whether they wanted to stay in power or not.

Mr. Conte, who is widely considered a puppet of his deputy prime ministers, Matteo Salvini, of the anti-immigrant League party, and Luigi Di Maio, of the anti-establishment Five Star Movement, pulled his only string to get the Italian government on some sort of track.