President Emmanuel Macron picked Sebastien Lecornu to be his fifth prime minister in two years on Tuesday, naming a loyalist who is unlikely to rip up his pro-business economic agenda.
Lecornu replaced Francois Bayrou, who was ousted in a parliamentary vote on Monday over his plans to trim the country's outsized budget deficit, the biggest in the euro zone.
Lecornu, most recently defence minister, said in a brief speech after a handover ceremony on Wednesday that the government would need "to be more creative, sometimes more technical, more serious", in how it works with the opposition.
But he also said "ruptures will be necessary".
Lecornu's immediate challenge will be how to steer a streamlined 2026 budget through parliament, which is split into three distinct ideological blocs.
Parties broadly agree on the need to slash France's deficit, which reached 5.8 per cent of GDP in 2024, but not on how to do it.
Lecornu has to send a full draft of the text to parliament by October 7, although there is some wiggle room until October 13, after which MPs will run out of time to pass the budget by year's end.
Reactions to Lecornu's appointment on Tuesday underscored the challenge he faces.
While the hard left said it would seek to topple Lecornu with an immediate no-confidence motion, the far-right National Rally (RN) signalled tentative willingness to work with him on the budget - as long as its budgetary demands were met.
"His budget will be RN or his government will not be," RN MP Laure Lavalette posted on X late on Tuesday.
The RN is France's largest parliamentary party and as such a crucial factor in any potential no-confidence motion.
Still, Lecornu is seen as the closest member of Macron's circle to the RN, having dined with RN president Jordan Bardella in 2024.
Lecornu's other path involves uniting the Socialists, who want to water down budget cuts and tax the rich, with his former party The Republicans, who are dead-set against any tax rises.
Macron, in an unusual step, called Socialist party leader Olivier Faure on Tuesday to tell him he would not be appointing a leftist as prime minister.
On Wednesday, Faure appeared to leave the door ajar to working with Lecornu, while also saying he would support a no-confidence measure if he felt the government didn't take on board its budgetary priorities.
Thousands of people across France meanwhile took to the streets as part of so-called "Block Everything" protests, an expression of broad discontent with Macron, proposed budget cuts and the entire political class.
