(Bloomberg) -- Italy’s Five Star Movement will boycott a key vote over an aid package Thursday, putting the survival of Prime Minister Mario Draghi’s government at risk.

Five Star leader Giuseppe Conte, who preceded Draghi as premier, said the country faces an unprecedented economic and social crisis, and that the government hasn’t listened to Five Star requests. Draghi strongly signaled he would hand in his resignation if Conte went ahead with his walkout.

The about face of Five Star -- which voted in favor of the government in the lower house as recently as Monday -- plunges Italy into instability just as the country grapples with an energy crunch, a drought and rising borrowing costs on its huge debt. It also threatens Italy’s resolute support for Ukraine, as Conte criticized weapon deliveries and instead urged to open negotiations with Russia.

“We are absolutely ready to give constructive support to this government and to Prime Minister Draghi, but we are not ready to give it a blank check,” Conte said on Wednesday evening after a day of meetings with allies and lawmakers. “This is not arrogance but attention to families and companies.”

The Rome Senate will hold a confidence vote Thursday on measures for businesses and households hit by high energy prices. Backing from other large parties, including the Democratic Party and the League, means that Draghi will win the Senate vote. 

But the premier has said that he would quit if Five Star walks out. Draghi is expected to meet President Sergio Mattarella after the vote.

For months, Draghi has been under pressure from several parties in his broad alliance who wanted him to soften reforms and possibly reshuffle the cabinet.

Five Star, which has been crumbling in opinion polls and saw Foreign Minister Luigi Di Maio quit the party, has been urging more generous help for workers and families. 

(Updates with context and details throughout)

©2022 Bloomberg L.P.