The most dangerous clown in France: Crackpot far-Left policies that would bankrupt the country. A 90% top tax rate. A burning hatred of NATO. Yet Jean-Luc Melenchon is now on the brink of becoming PM...

A bespectacled elderly man in a black leather jacket stomps up the stairs to his office and confronts the bearded plain-clothes policeman guarding the door.

Squaring up to the officer, his face within an inch of the other man's, he unleashes a spittle-laden rant.

'I'm telling you, you can't stop me from getting into my office,' he yells in fury. 'We aren't thugs or bandits. Go and do your job as a police officer! I am the republic! I'm a politician! Get out of my way and open this door!'

The star of this epic tantrum, which erupted in 2018 when police officers searched his office over allegations of the improper use of political funds – and was preserved for posterity on YouTube – was Jean-Luc Melenchon, the leader of an ultra-Left party called France Unbowed.

After his parliamentary grouping won more seats than any other party in the Left-wing coalition that emerged as the biggest bloc after last weekend's election, Melenchon is a contender to be France's next prime minister. It's a prospect that should terrify anyone with France's best interests at heart.

Jean-Luc Melenchon, the leader of an ultra-Left party called France Unbowed, is a contender to be France's next prime minister

Jean-Luc Melenchon, the leader of an ultra-Left party called France Unbowed, is a contender to be France's next prime minister

Melenchon first won elected office in 1983 when he became a local councillor in Massy, a town just outside Paris

Melenchon first won elected office in 1983 when he became a local councillor in Massy, a town just outside Paris

For Melenchon – who was given a three-month suspended prison term and an €8,000 (£6,700) fine following the unedifying confrontation outside his office – is the most dangerous clown in France, with the pomposity (and waistline) of Kim Jong Un.

It's initially hard to see how he can be taken seriously. But he's a mesmerising demagogue and the snake oil he is peddling appeals to his core vote, concentrated in densely populated suburbs of grim public housing with large immigrant populations. Just as in Islington, plenty of champagne socialists vote for him, too.

They all love his passionate support for Palestine, his intention to fling open the French borders and his instinctive hatred of the police.

Speaking of his intention to immediately lower the pension age to 60, which would bankrupt the state, Melenchon warned that any deputies who dare to vote against it 'will be named, registered and handed over to the People. That's democracy. I hope they will not be deported to a reform camp'. Was he joking? He's not renowned for his sense of humour.

If Melenchon got his way, he'd turn France into a European Venezuela and spark an exodus of wealthy citizens fleeing his proposed 90 per cent top rate of tax (unless they're put off by his exit taxes on anyone trying to leave).

Melenchon's positions are a toxic combination of Communism, alliances with militant Islamists and eco-radicals. He stands for higher wages and price controls on food and fuel, while nursing a burning hatred of America, Nato and Germany.

It adds up to a manifesto that's madder than one of those absurdist French farces by the national playwright, Moliere.

Yet now, by the slings and arrows of outrageous fortune, this wacky rabble-rouser, with a fondness for Mao jackets, who cultivates a 'man of the people' image despite having a net worth of €2.5million, is demanding the key to the Hotel Matignon, the headquarters of the French PM.

'Brothers in arms' Jeremy Corbyn and Melenchon, 72, speak outside the International Court of Justice in the Hague, Netherlands, in January this year

'Brothers in arms' Jeremy Corbyn and Melenchon, 72, speak outside the International Court of Justice in the Hague, Netherlands, in January this year

Melenchon was given a three-month suspended prison term and an ¿8,000 (£6,700) fine following an unedifying confrontation outside his office in 2018

Melenchon was given a three-month suspended prison term and an €8,000 (£6,700) fine following an unedifying confrontation outside his office in 2018

So how has this contemptible agitator risen to within touching distance of the second-highest office in the land?

A choir boy in his youth, Melenchon, a vigorous 72, is – like his brother-in-arms Jeremy Corbyn – a political lifer who, apart from a brief stint as a teacher as a young man, has never had a proper job. A member of the Internationalist Communist Organisation (OCI), a Trotskyist political party, from 1972 to 1976, he then joined the Socialist Party before splitting to found the Left Party, a coalition that allied itself with the French Communist Party.

Melenchon first won elected office in 1983 when he became a local councillor in Massy, a town just outside Paris. Three years later, he was elected to the Senate, the upper house of the French parliament, and – amazingly given his later flakiness –served as 'Minister for Vocational Education' from 2000 to 2002 for Lionel Jospin.

In 2009, he was elected to the European Parliament and went on to serve eight years an MEP.

He made the first of three attempts to win the French presidency in 2012, finishing with just over 11 per cent of the vote.

After founding 'France Unbowed' in 2016 and installing himself as its supreme leader, he finished in fourth place in the 2017 presidential election, with 19.6 per cent of the vote. He made his third and final presidential bid in 2022, winning 22 per cent of the vote but failed to reach the second round.

It is fair to say that, in his entire political career, he has achieved nothing beyond a reputation as a bully and fanatic – and yet he trousers a pay and allowances package of €10,000 a month, four times the average salary.

Now his hour may finally have come. Melenchon finds himself in the thick of a struggle to reconstitute a credible government – amid the shambles created by president Emmanuel Macron's unfathomable decision to call a snap election, and after Marine Le Pen's hard-Right National Rally's surprise performance in the European parliament elections.

Repairing the political devastation he's wreaked is an operation of bewildering complexity and one that may not be possible. Fifteen factions are now represented in the National Assembly and they don't play nicely together.

Putting together a coalition to succeed the government Macron dismissed is akin to solving a Rubik's Cube while blindfolded. And God help France if Melenchon ever emerges a winner.

Macron has been Melenchon's witless enabler. Macron let him into his tent. Now he's refusing to leave. Yet despite the bombast, Melenchon's extreme Leftists actually lost ground in the final results after Macron's cack-handed electioneering, winning only 11 per cent of the popular vote (versus 37 per cent for Le Pen) and falling from 77 to 74 seats in the 577-member assembly. His belief that he has won some kind of mandate is symptomatic of his boundless self-importance.

Melenchon would plunge France into the mother of all economic, social and political crises but, in his customary intemperate fashion, is threatening anyone who defies him. If he's not given the reins of power, he vows to take his supporters on to the streets.

Meanwhile, Marine Le Pen – who got a higher percentage of the vote in France than Keir Starmer did in Britain – has been exiled to opposition.

But if Macron's intention was to destroy her, he has failed. She's proved again and again that whatever doesn't kill her makes her stronger.

What emerges from the machinations in Paris could be a technocratic government, managing daily affairs but with no legislative agenda. Or some kind of benevolent national government of all the talents, which seems more of a dream than immediate prospect, given the egos involved.

The alternative is an unstable coalition with a shelf-life of perhaps weeks or days.

It is earnestly to be hoped that no matter how much France seems to have had the nervous breakdown I have long predicted, cooler heads will prevail. And, as a new order emerges, Jean-Luc Melenchon is allowed nowhere near any of it.