Italian leaders get behind French yellow vest revolt

"Yellow vests, do not weaken!", Luigi di Maio, Italy's other deputy prime minister, added.

Di Maio, from the Five Star Movement (5MS) party in Italy's ruling coalition, also offered yellow vest leaders the use of his party's IT platform, called Rousseau, to help organise future events in France.

"We would be happy if you want to use it," Di Maio said on the 5MS blog.

Yellow vest protests broke out in French regions in November against fuel taxes.

They spread to cities and became a wider protest against social inequality under Macron.

They also turned violent, with riots in central Paris in the past eight weeks, accidental fatalities, and 5,600 arrests.

Italy's Salvini "firmly" condemned the violence and Di Maio "disapproved" of it.

But the two men's extraordinary intervention in a fellow EU state's civic unrest crisis comes amid personal and ideological enmity.

Macron has pitted himself against Salvini as the head of a liberal pro-EU front against the Italian's anti-EU league in the coming European Parliament (EP) elections.

The French president, a former investment banker, is also a bogeyman for 5MS-type populism, with Di Maio, on Monday, ramming the idea home.

Macron represented "the interests of the elites, those who live off privilege, no longer those of the people," Di Maio said on his blog.

"A new Europe is being born. That of the 'yellow vests', that of movements, that of direct democracy. It's a tough battle that we can win together," Di Maio added.

The Rousseau IT platform is designed to help organise events on the ground, select candidates, and draft electoral programmes in what could help transform the French yellow vest movement into a political party.

Salvini and Di Maio's foray into French politics comes as both men seek recruits for new EP groups after the EU elections in May.

Salvini is trying to pull in right-wing Austrian, French, Dutch, Polish, and Swedish parties into a eurosceptic and anti-migrant league.

Di Maio is trying to pull right and left-wing anti-establishment voters into a pro-euro but anti-austerity group, which he aims to unveil this month.

But for its part, France is to focus on security preparations for the next potential flashpoint.

There would be 80,000 police and gendarmes on the streets of French cities, 5,000 of them in Paris, next weekend, French prime minister Edouard Philippe said on Monday.

Known violent offenders would also be blacklisted from attending protests under a draft new law, he added.

"We must preserve the freedom to demonstrate in France and must punish those who want to violate this right to demonstrate," Philippe said.