LIf the measure passes on Wednesday, as is expected, it would mark the first time a French government has been removed this way in more than 60 years.

The National Assembly is due to vote after debating two motions introduced by the left-wing camp and far-right nationalists, which together count more than 330 politicians. A no-confidence motion requires at least 288 of 574 votes to pass.

The far-right National Rally (RN) of three-time presidential candidate Marine Le Pen is expected to vote for the motion put forward by the left, giving it enough numbers to pass.

The session is due to start at 4pm (15:00 GMT), with voting expected hours later. President Emmanuel Macron is set to return to France from a state visit to Saudi Arabia during the day.

Macron, whose term ends in 2027, has dismissed the threat of his potential removal from office amid the turmoil, saying such discussions were “make-believe politics”.

I am here because I’ve been elected twice by the French people,” Macron was quoted as saying by French media. “We must not scare people with such things. We have a strong economy.”

But the toppling of the Barnier government after just three months in office would leave the president with few options over how to go forward and who to appoint in his place.

No new elections can be called for a year after the previous legislative polls. Macron could ask Barnier to stay on in a caretaker role as he seeks a new prime minister, which could happen only next year.

Asked on French television if there was a chance his government could survive Wednesday’s vote, Barnier replied: “I want this and it is possible. It depends on the MPs,” he said.

The latest political turmoil follows snap elections called by Macron in June in a bid to halt the surge of the far right, which left no party or faction in parliament with a majority.

Some observers have suggested that Le Pen, 56, is seeking to bring down Macron before his term ends by ousting Barnier. The far-right leader is embroiled in a high-profile embezzlement trial and, if found guilty in March, could be blocked from participating in France’s next presidential election in 2027.

She has insisted that the party’s stance was entirely due to a budget that would make the French poorer. “Censuring the budget is for us the only way the constitution gives us to protect the French,” Le Pen told reporters as she arrived in parliament.

If the government falls, it would be the first successful no-confidence vote since a defeat for Georges Pompidou’s government in 1962, when Charles de Gaulle was president.

Opposition parties tabled the motion after the former Brexit negotiator controversially used special powers to force through his budget without a vote.

Barnier pleaded his case on French television on Tuesday night and said it was “possible” he could survive Wednesday’s vote.

But opposition parties on the left and right are expected to unite to remove him, fuelling the political instability which has gripped France since summer elections produced a divided parliament, and increasing the pressure on Macron.

France has been beset by political uncertainty since snap elections in June and July called unexpectedly by Macron led to no single group having a majority in parliament.

While a left-wing alliance won most seats, Macron appointed the conservative Barnier in a bid to reinstate stability – but his government has been consistently undermined because it does not have a majority.

On Monday, Barnier opted to push through controversial reforms to social security by invoking presidential decree after failing to win enough support for the measures, a move which has left his minority government on the brink of collapse.

Speaking to French television, Barnier rejected the idea that President Emmanuel Macron should resign to unblock the country’s current crisis, calling him a “guarantee of stability”.

Barnier also said he remained open to budget talks with opposition parties despite being widely predicted to lose the vote, and sought to distance himself from France’s ongoing state of political instability, saying he was not at fault.

In the interview with the TF1 and France 2 television channels, Barnier said: “It’s not a question of political survival for me.

“I’ve been in this office for three months. I arrived there on 5 September, telling myself that I could leave the next morning,” he added.

“This is the first time since 1958 that there is no majority at all. No majority possible between three major groups. I know that this is a fragile and ephemeral situation.”

The budget bill sought to deliver €60bn (£49bn) in tax rises and spending cuts.

Barnier was forced to cave in to changes demanded by critics due to his lack of a parliamentary majority.

He is now expected to become the shortest-lived prime minister in France’s Fifth Republic, with the left wing bloc in the National Assembly, as well as the far-right, predicted to back the motion against him.

If he does not survive the vote, he will remain in place as caretaker prime minister until Macron announces a new government.

While Macron – who is on a state visit to Saudi Arabia – has reportedly begun considering his pick for the next prime minister, the process could take weeks, as it did in summer.

Furious opposition parties said they would back a no-confidence motion to oust the former Brexit negotiator in a vote that could take place as early as Wednesday.

Barnier opted to push through controversial reforms to social security by invoking presidential decree after failing to win enough support for the measures.

One left wing French MP said that the move had left France in “deep, huge political crisis”.

France has been beset by political uncertainty since President Macron called snap elections over the summer which resulted in a hung parliament where no party had an absolute majority.

A left-wing alliance won most seats, and the conservative Barnier – appointed by Macron to bring stability to the French government – has faced the constant threat of a vote that could force him out.

While Barnier had made last-minute concessions to the social security funding bill – which sought to rein in France’s spiralling deficit – his efforts were insufficient to get it over the line.

Certain that the National Assembly would reject the bill, Barnier used executive powers under article 49.3 of the French constitution to force it through.

“I don’t think French people will forgive us for choosing party interests over the future of the country,” Barnier told MPs on Tuesday as he explained the reasons for his decision. “Now, everybody will need to assume their own responsibility as I have assumed mine.”

Almost immediately, the left wing opposition party France Unbowed (LFI) and Marine Le Pen’s far-right National Rally (RN) said they would table no-confidence votes.

Le Pen told reporters in parliament that “the French have had enough”.The budget bill sought to deliver €60bn (£49bn) in tax rises and spending cuts.

But Barnier was forced to cave to changes demanded by critics due to his lack of a parliamentary majority.These included scrapping a previously planned hike in electricity tax, as well as plans for a less generous prescription drug reimbursement policy from next year.

The new version remained unacceptable to the opposition, with the RN joining the left in opposing it.

Barnier has warned of the financial and political effects of unseating him, but Mathilde Panot, president of the LFI, said on Monday that “there will not be chaos once Mr Barnier and his government have gone”.

“We are now experiencing political chaos as a result of both Mr Barnier’s government and Emmanuel Macron’s presidency.”

Nathalie Oziol, an MP with the hard left France Unbowed said that France was in a “deep, huge political crisis”.

“One sure thing is that this government has not led to any form of stability, that Macron’s politics have not led to any form of stability – and that has worsened in the last month,” the MP said.

If Barnier doesn’t survive Wednesday’s no confidence vote, he will remain in place as a caretaker prime minister until Macron announces a new government.

That could be a new majority government – unlikely given the splintering of the French parliament – or a technocratic government, to steer the country until new elections can be held next summer.

The process could take weeks, as it did after a snap general election delivered a hung parliament in summer.

Several parties are also clamouring for new presidential elections. As it stands, Macron is due to stay in post until 2027.If the government does not survive the vote, the budget bill will fail too.