ROME — The head of Italy’s 5-Star Movement said late Wednesday the party’s lawmakers won’t participate in a confidence vote in the upper chamber of Parliament, putting the stability of Premier Mario Draghi’s coalition government at risk.

Former Premier Giuseppe Conte announced the move in a late-night briefing with 5-Star lawmakers.

The vote on a series of measures to help Italians withstand the economic crisis is scheduled for Thursday in the Senate and is tied to a confidence motion. Such confidence motions on government-sponsored bills are designed to ensure allies close ranks, but Conte announced, “We won’t participate in the vote.”

The 5-Star Movement is a key coalition partner in Draghi’s government of national unity, formed with parties on the right, left and the populist 5-Star to help Italy recover from the coronavirus pandemic.

The 5-Star leadership has been complaining for weeks about government priorities, demanding more generous financial relief for families and businesses slammed by high energy costs and continued funding of a guaranteed monthly salary for those unable to find work.

Draghi has tried to respond, but he made clear this week that he wouldn’t act on ultimatums.

It remains unclear if Draghi’s government would still command a majority without 5-Star lawmakers, given so many have defected or been expelled since the movement first swept to national power in 2018 elections, when it became the biggest party in Parliament.

The center-right, which has done well in recent local and administrative elections and has been leading the polls, has said early elections would be the only solution if the 5-Star senators abstain from a confidence motion of their own government.

Conte insisted he still supported Draghi and would work to find solutions to the 5-Star demands. But, he added, “We have asked for a change in the exclusive interest of citizens.”