John Lichfield was Paris correspondent of The Independent for 20 years. Half-English and half-Belgian, he was born in Stoke-on-Trent and lives in Normandy.

In early December, Jupiter fell from the sky.

Yellow-vested hordes had ravaged Paris. There was talk of a civil war. Jupiter, aka Emmanuel Macron, disappeared from public view. He was silent and, some say, scared. He secretly visited the nuclear bunker below the Elysée Palace, just in case.

Three months later, Jupiter is back in his heaven.

He has written a letter, in 24 languages, to the peoples of Europe. He has started a “Great Debate” on the future of France. He has soared, modestly, in the French opinion polls from 23% to 34%.

Emmanuel Macron has started talking again. And it seems that he doesn’t know when to stop. He spent 14 hours, a French presidential record, talking to farmers at France’s annual agricultural show. He also regularly spends six or seven hours in his shirt-sleeves answering questions in village halls as part of his Great National Debate.

His 1,700-word letter, or op-ed, published by newspapers in all 28 EU countries, called for radical new common European policies on trade, competition, defence, social media, industrial research, climate and immigration.

What has changed? Could this wiser and bolder Macron put the Yellow Vest rebellion behind him and re-ignite his presidency with an unlikely “mid-term” victory for his centrist party in the European elections in May?

Macron's cunning plan for Europe By John Lichfield

Might he manage to claim the de facto leadership of Europe as Angela Merkel drifts into retirement? And, with the British awkward squad out of the way, could he reshape the European Union to France’s liking? Could he bring to fruition his vision of a “protective” EU which defends European “economic sovereignty” against China and America and defends European liberal democracy against nationalism, populism and Russia.

To British eurosceptics, Macron’s Letter to Europe and his appeal for an “EU renaissance” was an arrogant imposition – but also a windfall. Here was a man confronted with popular rebellion in France who was lecturing Britain about the “lies and irresponsibility” of Brexiteers. Here also was a French president calling for centralised new policies for defence, climate, migration and research. Here was proof that the EU was frog-marching (no pun intended) its peoples towards a federal state.

Macron's cunning plan for Europe By Matthew Goodwin

Seen from the French end of the Channel Tunnel, though, there is no contradiction between a Macron who is under populist siege at home and a Macron who is trying to set a new agenda for Europe. The passage in his op-ed attacking Brexiteers – “anger mongers, backed by fake news, (who) promise anything and everything” – was also aimed at the dottier theories and demands of the Gilets Jaunes (yellow jackets). His appeal for a more “protective” EU, devoted to European “economic sovereignty”, was a response to the anti-market, anti-globalist rhetoric of French Hard Left and Far Right.

Macron’s Letter to Europe was – perhaps first and foremost – a Letter to France. It was, in effect, his manifesto for the European elections at the end of May. Even before the Gilets Jaunes rebellion exploded, Macron had incautiously made the European poll a plebiscite on his first two years in office. He had spoken of making the European elections an EU-wide referendum for or against the “leprosy” of nationalism and populism.

He now fights the election on 26 May against the backdrop of the most prolonged period of popular unrest in France since World War Two. Opinion polls put his centrist party, La République En Marche (LREM), neck-and-neck with Marine Le Pen’s far-Right Rassemblement National – at around 22 to 24 % of the total vote.

If LREM tops the poll, even by one per cent, it will make no technical difference to the remaining three years of Macron’s presidency. Having an extra Macroniste Euro MP or two is of little practical importance.

Macron's cunning plan for Europe By John Lichfield

But it would be a remarkable victory. It would re-launch a presidency which recently appeared doomed to the one-term failure of his predecessors Nicolas Sarkozy and François Hollande. In no EU country since European elections began 40 years ago has so much depended on the results of a European poll.

To “win” Macron must motivate and mobilise the young, urban, European-minded voters who often cannot be bothered to vote in European elections. His Letter to Europe was, above all, aimed at them.

In past years, the European elections have attracted only 40% of registered voters in France, compared to 70% in national elections. Recent surveys suggest that over 50% of the French plan to vote on 26 May.

President Macron is praying that those “new” voters are young, urban pro-European and pro-Macron and not provincial, embittered and pro-Yellow Jacket or far Right or far Left. He has weathered the worst of the Gilets movement. He has recovered his confidence and has risen in the polls for the first time in a year. But his domestic situation remains fragile and hazardous.

The Gilets Jaunes have lost strength (less than 40,000 turned out last weekend, compared to 243,000 in mid-November) but they have not gone away. They have now protested in French cities for 16 weeks in a row and a special three-day protest is planned for “Act 17” this weekend. They have become a slow-motion insurrection, a weekends-only putsch, which wants to topple Macron and impose a form of grass-roots government via the internet.

Macron's cunning plan for Europe By David Patrikarakos

But the violence and anti-semitism of some Gilets Jaunes has eroded much of the public’s support. Furthermore, Macron’s €10bn package of concessions in December, including extra public aid to people on the minimum wage, took some wind from the yellow sails. Even more important in swaying public opinion, arguably, has been the Great National Debate, an idea that Macron dreamed up in his panic of early December.

But while the debate has thus far proved to be an extraordinary success, it could yet turn into a trap. There will have been over 6,000 public meetings by the time the debate ends next week with hundreds of thousands of contributions submitted on the internet.

In theory, the public’s views will be synthesised by mid-April into a series of proposals on taxation, more efficient government, political representation and the environment. Macron is considering whether he will put these ideas to a referendum in June or September.

The Gilets Jaunes, though, are waiting in ambush. If the ideas which emerge from the Great Debate are bland and minimal (as seems probable), they plan to detonate a second wave of rebellions when the weather turns warmer in spring and early summer. Just in time for the European elections.

But let us assume, though, that he prevails. Let us leave aside the uncertainties surrounding Brexit, and assume that his Letter to France wins the day for him. How achievable is the French president’s vision for Europe?

Macron's cunning plan for Europe By John Lichfield

His ambition is clear. Macron has called for a conference of EU countries at the end of the year to plot the way ahead; Angela Merkel’s Cheshire Cat-like fade-out from German and European politics does seem to offer a leadership opportunity. But while he can talk a good game, how much can he achieve?

His plans for new EU spending in areas such as health, climate, high-tech research and defence won’t go far. Post-Brexit quarrels already loom on how to fund the existing EU budget and how much of it to spend on agriculture. In these battles, France and Germany line up on opposite sides.

The one area in which France and Germany may see eye to eye, though, is Macron’s ideas for “European economic sovereignty”. He wants to change the EU’s rules on “fair and free” competition to allow the emergence of European industrial and financial “champions” – in effect new “European airbuses” for rail manufacture, batteries, artificial intelligence and maybe banking. He also wants to allow “European preference” in public procurement policies.

The idea is to enable Europe to defend itself against “bullying” by giant Chinese or American corporations in the decades ahead. Some German politicians, including the economy minister Peter Altmaier, agree. Britain would have been fiercely opposed but Britain will, probably, have departed. Other free-market countries, notably the Netherlands, will object but will find themselves isolated.

Macron's cunning plan for Europe By John Kampfner

It is reasonable to expect, in the years ahead, a significant shift in EU doctrine towards long-held, interventionist French ideas. Some progress is also likely on Macron’s proposals (but not entirely his own) for an EU-wide policy to protect European democracies from automated fake-news production lines on the internet. The target here is Russia. Expect resistance from some eastern European countries (Poland and Hungary) but support from others.

There is an intellectual and political coherence to Macron’s European ideas. They are all intended to answer the Great Eurosceptic Question: what does Europe do for us? Even Viktor Orban, the Hungarian Prime Minister, accused by Macron of being part of a “leprosy” of rising nationalism, praised the French president’s letter as a “step in the right direction”.

From trade, to immigration, to research, to democracy, Macron wants to encourage Europeans to see the EU as something that “protects” them. He seeks ammunition to fight the nationalist-populist argument that the EU is a distant, abstract bureaucracy which tramples national interests or values.

But let’s consider and savour the paradox. He talks of creating a Europe-wide backlash against nationalism. He needs European ammunition to win a European election. His European views are, no doubt, sincere. But his most pressing motivation, and the biggest immediate stakes, are personal and domestic – to save his own presidency.