France is at a critical juncture due to uncertainty over the country's budget and the future of the government, Finance Minister Antoine Armand said on Tuesday.

Expectations that Prime Minister Michel Barnier's government will collapse this week have hit the stock and bond markets of France, the eurozone's second-biggest economy, which is under pressure due to its rising deficit.

"The country is at a turning point," Armand told France 2 TV, adding politicians had a responsibility "not to plunge the country into uncertainty" with a no-confidence vote.

Barnier is due to address television news programmes around 1900 GMT, and is expected to face no-confidence motions as early as Wednesday. Barring a last-minute surprise, his fragile coalition will be the first French government to be forced out by a no-confidence vote since 1962.

A government collapse would leave a hole at the heart of Europe, with Germany also in election mode, weeks ahead of U.S. President-elect Donald Trump re-entering the White House.

Barnier's budget, which seeks to rein in France's spiralling public deficit through $62.9 billion in tax hikes and spending cuts, has been opposed by politicians on both the left and far right.

The left and the far right combined have enough votes to topple Barnier, and National Rally leader Marine Le Pen confirmed on Monday that her party would vote for the left-wing coalition's no-confidence bill as well as her own.

"The French have had enough," she said.

Barnier's minority government had relied on RN support for its survival. His entourage and Le Pen's camp each blamed the other and said they had done all they could to reach a deal and had been open to dialogue.

If the no-confidence vote does indeed go through, Barnier would have to tender his resignation but Macron could ask him to stay on in a caretaker role as he seeks a new prime minister, which could well happen only next year.

In any case, there can be no new snap parliamentary election before July.

As far as the budget is concerned, if parliament has not adopted it by December 20, the caretaker government could propose special emergency legislation to roll over spending limits and tax provisions from this year. But that would mean that savings measures Barnier had planned would fall by the wayside.