French Prime Minister Michel Barnier was set to hand in his resignation on Thursday after far-right and leftist lawmakers voted to topple his government, plunging the euro zone's second-largest economy deeper into political crisis.

Barnier, a veteran politician who became prime minister barely three months ago, will become the shortest-serving prime minister in modern French history when President Emmanuel Macron approves his resignation.

The two men met for over an hour, French media said, adding that Barnier had now left the Elysee presidential palace. However, there was still no official confirmation of his resignation.

Any new prime minister will face the same challenges that led to Barnier's downfall, including in particular pushing the 2025 budget through a deeply divided parliament at a time when France needs to fix ailing public finances.

Much focus will also be on Macron himself after an online poll showed 64% of voters want him to resign.

Meanwhile, Macron will embark on trying to find a new prime minister.

Three sources told Reuters that Macron aimed to appoint a replacement swiftly, with one saying he wanted to name a premier before a ceremony to reopen the Notre-Dame Cathedral on Saturday, which U.S. President-elect Donald Trump and other global political leaders are due to attend.

The political turmoil in France further weakens a European Union already reeling from the implosion of Germany's coalition government, and comes just weeks before Trump returns to the White House.

The hard left and far right punished Barnier in a no-confidence vote on Wednesday evening for trying to push a social security budget through an unruly hung parliament without a vote.

Macron is 'main culprit'

Macron precipitated the ongoing crisis with an ill-fated decision to call a snap election in June. He has a mandate until 2027 but faces growing calls to resign.

"The main culprit for the current situation is Emmanuel Macron," Marine Le Pen of the far-right National Rally (RN) told TF1 TV late on Wednesday.

"The dissolution (of parliament in June) and censorship (of the government) are the consequence of his policies and of the considerable divide which exists today between him and the French."

No French government had lost a confidence vote since that of Georges Pompidou in 1962.

A small majority of voters approved of parliament bringing down Barnier, but many are worried about its economic and political consequence, according to the Toluna Harris Interactive poll for RTL broadcaster.

Under French constitutional rules, there can be no new parliamentary election before July.

"Until potential new elections, ongoing political uncertainty is likely to keep the risk premium on French assets elevated," SocGen analysts said in a note. "Political uncertainty is likely to dampen both investment and consumer spending."

The political uncertainty has already been unnerving investors in French sovereign bonds and stocks for weeks.