This is the second time in a year the ruling party sinks its own Cabinet.
“I am leaving with my head held high,” Tudose said after party leaders voted to withdraw his political backing.
Tudose’s resignation comes after he called on Interior Minister Carmen Dan to resign, accusing her of lying. Dan, a close ally of party leader Liviu Dragnea, refused to resign.
Last year, the social democrats ousted their own government in a no-confidence vote due to a rift between Dragnea and the previous prime minister, Sorin Grindeanu. Dragnea himself cannot become prime minister due to a conviction for vote rigging.