French Prime Minister Michel Barnier invoked a special constitutional tool on Monday to push through the controversial 2025 budget without a parliamentary vote.
Mr Barnier said it was necessary to ensure stability at a time of deep political divisions.
Marine Le Pen’s National Rally and the leftist France Unbowed announced they would file no-confidence motions in response, setting up a vote for as early as Wednesday that could bring down the fragile government.
The decision comes as France grapples with a fractured National Assembly following snap elections in June, which left no party or coalition with a majority.
President Emmanuel Macron appointed Mr Barnier in September to break the deadlock and tackle the country’s ballooning deficit.
However, his austerity budget— featuring 40 billion euros in cuts and 20 billion euros in tax hikes — has been widely criticised, escalating tensions in the lower house.
The use of the tool, called Article 49.3, allows the government to pass legislation without a parliamentary vote but leaves it exposed to no-confidence motions.
Opposition leaders argue that Mr Barnier’s concessions, including scrapping an electricity tax hike, do not go far enough to address their concerns.
Ms Le Pen accused Mr Barnier of ignoring her party’s demands.
“Everyone must shoulder their responsibilities,” she said.
The political standoff has unsettled financial markets, with borrowing costs rising sharply amid fears of prolonged instability.
Mr Barnier warned of “serious turbulence” if the budget isn’t passed, but critics dismissed his remarks as fear-mongering.
If the no-confidence motion succeeds, Mr Macron will remain president but will need to appoint a new prime minister to steer legislation through the fractured assembly.
The uncertainty threatens to deepen France’s economic troubles and reverberate across the eurozone.