The French President claimed “Europe’s inability to protect people” is responsible for the rise of anti-establishment parties across the union.
And he insisted the only solution was “a more united Europe”, not more national sovereignty.
Touching on the UK’s historic decision to split from Brussels, Mr Macron bundled Brexit in with other European populist movements, which he said “feed on the fact that no one can explain things.”
The French leader was speaking in Rome following a two-day summit with his Italian counterpart Paolo Gentiloni, who is facing the very real prospect of an election defeat in March.
Mr Macron said: “Look at the situation in Europe. Why does populism win?
“That’s what you must ask yourself, not the fact of having a European ambition. The lack of this this ambition is precisely what has let populism grow.
“That’s why we want a more united Europe.
“When on the commercial and social areas, on borders… we have a Europe that knows how to respond to the needs of Europeans, populism decreases.”
In a show of support for Italy’s Prime Minister, Mr Macron gushed about how pleased he was the pair were working together.
Mr Macron said: “I want to stress how happy I have been to work with Paolo Gentiloni in recent months.
“His efforts in Italy and Europe have made it possible to create a new dynamic.”
Italy is set to head to the polls on March 4, and Mr Gentiloni’s ruling Democratic Party (PD) is facing an uphill struggle against the populist 5-Star Movement (M5S).
Polling from earlier this month shows the anti-establishment M5S with a lead of between four and seven percent.
Mr Gentiloni’s centre-left PD also faces threats from the Forza Italia party, led by former PM Silvio Berlusconi, which has polled third for several months.
In addition to strengthening ties between France and Italy, Mr Macron, who recently turned 40, is in Rome to advance his plans for greater integration between EU member states.
His ambitious proposals include a major overhaul of the union’s institutions, a banking union and a new eurozone budget which could be used to bail out struggling EU economies.
His plans have already come under fire from some Dutch politicians, and he will need the full support of German Chancellor Angela Merkel, who is struggling to form a government after a poor election showing.
And he is unlikely to achieve any major change if more populist and anti-establishment parties win power across Europe.
And while Mr Macron appears to have convinced the so-called “Club Med” nations – Spain, Greece, Portugal, Malta and Cyprus – to get on board, he is likely to have a much harder time convincing all 27 member states.
Speaking following a meeting with “Club Med” leaders yesterday, Mr Macron said: “On European monetary union and the euro zone, we have a real proximity of views and a real ambition.
“We have a clear convergence of views to advance on finalising a banking union and to go toward a veritable budgetary union.”
But he admitted the next challenge is “to convince our partners.
He added: “Because we need to complete a real financing union that will allow more growth and a better coordination of our policies.”