Barring a last-minute surprise, Prime Minister Michel Barnier's government will be France's first to be forced out by a no-confidence vote in more than 60 years, at a time when the country is struggling to tame a massive budget deficit.
That would leave a hole at the heart of the European Union at a time when Germany is also weakened and in election mode, weeks before U.S. President-elect Donald Trump re-enters the White House.
In a TV interview on Tuesday, Barnier said he still believed his government could survive the vote, scheduled for Wednesday evening after a debate starting in the afternoon.
But far-right National Rally (RN) chief Jordan Bardella confirmed on Wednesday that his party would vote to topple Barnier alongside left-wing parties.
He said Barnier's optimism showed that the government was "completely out of touch with what is happening in the country".
"This government is dangerous for my country," he told France Inter radio.
President Emmanuel Macron brought on the crisis by calling parliamentary elections in June. (AP PHOTO)
"We will vote for the no-confidence motion."
Barnier's interior minister, Bruno Retailleau, was downbeat.
"Nothing's over until the vote but we can see we're headed towards censure (of the government)," he told CNews.
President Emmanuel Macron, who won a second mandate in 2022, precipitated the crisis by calling a snap parliamentary election in June.
His term as president runs until mid-2027 and he cannot be forced out by parliament, but the RN and the hard left have already been saying he should resign as he faces his biggest crisis since the Yellow Vest popular unrest of 2018-2019.
Since Macron called the election, France's CAC 40 has dropped nearly 10 per cent and is the heaviest loser among top EU economies.
The single currency is down nearly four per cent.
Barnier's draft budget had sought to cut the fiscal deficit, which is projected to exceed six per cent of national output in 2024, with 60 billion euros in tax hikes and spending cuts.
It sought to drag the deficit down to five per cent in 2025.
The caretaker government could propose emergency legislation to roll over spending limits and tax provisions from 2024.
But that would mean Barnier's savings measures falling by the wayside.
Barnier says the consequences of voting him out will be catastrophic for state finances, but RN MP Laure Lavalette told TF1 TV: "There is no reason for this to lead to major chaos. Don't play with fears ... it's not all going to crumble."
If the no-confidence vote passes, Macron may well ask Barnier to stay on in a caretaker role as it could take until 2025 to find a new prime minister.