France’s looming political crisis proves that Brexit was about “more than just Britain”, a leading light in the Vote Leave campaign has said, adding: “The cracks are starting to show.”

Lee Rotherham was speaking on the day before French Prime Minister Michel Barnier - ironically, the bloc’s former chief Brexit negotiator - was facing a crunch confidence vote in the country’s National Assembly.

If, as seems likely, Mr Barnier - who was only appointed by President Emmanuel Macron in September - loses, he will have little choice but to resign, plunging one of the EU’s cornerstone nations into months of chaos. In a probable hint of future unrest, thousands of protesting taxi drivers caused gridlock on the roads of Paris yesterday.

Mr Rotherham, who was Vote Leave’s director of special projects, told Express.co.uk that the growing discontent was related to a wider malaise running through the continent.

He said: “The cracks are starting to show.

“No one should be surprised that tensions build up over decades. Brexit was not a purely British phenomenon. But with each passing year, untangling the circuitry of these laws becomes harder and harder for every country still in the EU.”

Mr Rotherham pointed out that it was easy to forget just how rapidly France had “churned through Republics,” most recently in 1958.

He explained: “In the 1950s the country was averaging two governments a year, which makes recent British history look in comparison like a model of constancy.

"De Gaulle introduced stability during the Algerian crisis by changing the constitution to make the system more presidential and more centralised. But this comes at a cost."

Mr Rotherham suggested that, like in other Western countries, many ordinary people perceive a “distance" between their own aspirations and priorities and those of the "bureaucrat elites that govern them."

He continued: "That alienation is very dangerous in a democracy, and obviously if you leave a political gap, someone will fill it. If that’s not a mainstream party, it will be a new radical party; and if there’s no radicals, it will be by extremists."

In the case of France and Germany - unlike the UK - the EU was also" in the mix" as an extra level of bureaucracy which was "even more distant and unaccountable”, Mr Rotherham stressed.

He added: "Very few politicians genuinely know how laws are actually made. They will know of the European Parliament of course, and about the bartering behind closed doors by ministers. A few may even be aware of the national diplomats secretly discussing texts in committees before then.

"But these are very low down the legislative stream, well after the key drafting decisions have been made behind closed doors by invisible Eurocrats and hundreds of unknown advisory groups of lobbyists and delegates.

“That complicated decision chain makes for poor accountability. Bad decisions can rarely be fixed, even when they become newspaper scandals.

"That in turn feeds into public discontent, who see bad law-making and no one who seems interested let alone able to do anything about it.”

Mr Barnier is bracing for a no-confidence vote tomorrow after yesterday invoking a rarely used constitutional mechanism to push through the contentious 2025 budget without parliamentary approval, arguing it was essential to maintain “stability” amid deep political divisions.

The move immediately drew sharp backlash, with Marine Le Pen’s far-right National Rally and the leftist New Popular Front both filing no-confidence motions in response, setting the stage for a vote which could see Mr Barnier lose his job

The looming showdown unfolds against the backdrop of a fractured National Assembly, left in disarray after June’s snap elections failed to deliver a clear majority.

If the no-confidence motion succeeds, Mr Macron will remain president but must 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.