French far-right presidential candidate Eric Zemmour was left lightly injured after being assaulted at his first campaign rally on Sunday where fighting also broke out during his speech in front of thousands of supporters.

The 63-year-old author and television commentator suffered a wrist injury when a man grabbed him violently as he made his way towards the stage at a giant exhibition centre northeast of Paris on Sunday afternoon, an aide told AFP.

The rally was his first official campaign event since his announcement on Tuesday that he would seek to unseat centrist President Emmanuel Macron in next April's election.

Eric Zemmour's poll ratings have faded since a splashy entrance into the French presidential campaign
Eric Zemmour's poll ratings have faded since a splashy entrance into the French presidential campaign AFP / Thomas SAMSON

"The stakes are huge: if I win it will be the start of winning back the most beautiful country in the world," Zemmour told the crowd in Villepinte which cheered his anti-immigration rhetoric loudly.

Shortly after he started speaking, fighting broke out and chairs were thrown at activists who stood up with "No to Racism" written on their T-shirts.

"We wanted to do a non-violent protest," Aline Kremer from the group SOS Racisme, which organised the stunt, told AFP. "People jumped on them and started hitting them."

Profile of Eric Zemmour, candidate for the French presidential election
Profile of Eric Zemmour, candidate for the French presidential election AFP / Kenan AUGEARD

A crew from the popular but critical Quotidien nightly TV news show was also booed and briefly removed by security, with hostility to the media a feature of Zemmour's and other speeches at the event.

Many Zemmour supporters back his campaign 'so that France remains French'
Many Zemmour supporters back his campaign 'so that France remains French' AFP / JULIEN DE ROSA

The rally was seen as a chance for the best-selling author to regain momentum after opinion polls showed support for him falling over the last month.

"We're hoping that by announcing his candidacy and with this rally that it will relaunch him a bit," said Maxence Mike, a 22-year-old student member of the "Generation Z" support group.

Zemmour, who has two convictions for hate speech, claimed there were 15,000 people at the rally, although organisers had previously talked of 12,000.

Polls suggest that voters currently believe Marine Le Pen, the veteran leader of the far-right National Rally party, would make a more competent president than Zemmour.

The latest surveys suggest he would be eliminated in the first round if the election were held now, with Macron tipped to beat Le Pen in the second round, but analysts warn that the outcome remains highly uncertain.

'If I win it will be the start of winning back the most beautiful country in the world,' Zemmour told the crowd
'If I win it will be the start of winning back the most beautiful country in the world,' Zemmour told the crowd AFP / Stefano RELLANDINI

Zemmour vowed that if elected he would reduce immigration to almost zero, dramatically tighten the naturalisation process, and expel failed asylum-seekers and illegal immigrants.

He again stressed the danger of French people being "replaced" by immigrants, echoing a theory known as the "great replacement" that is popular with white supremacists.

The idea was on many supporters' minds.

"You just need to go out in the street to see it," Helena, a 60-year-old civil servant from the Paris suburbs, told AFP at the rally. "When I take public transport I barely hear anyone speaking French."

Fabrice Berly, a 54-year-old photocopier technician also from the Paris suburbs, said he no longer recognised his neighbourhood as the same place he grew up in.

"I can see the replacement going on around me," he said.

Jacques Ohana, a 65-year-old Paris surgeon, said Zemmour had already succeeded in making immigration one of the main topics of the election campaign.

"Whether he's elected or not, he's already won the campaign," he said.

France's right-wing Republicans party picked the boss of the Paris region Valerie Pecresse as its nominee on Saturday after a primary dominated by talk of immigration and crime.

Police were on alert for far-left activists and anarchists who disrupted Zemmour's trip to the southern of port city of Marseille last weekend, which ended with the candidate showing the middle finger to one protester.

Riot police massed outside the arena and searched people's bags as they arrived.

As well as a series of recent missteps, including the middle-finger incident, Zemmour has seen several influential figures on the far right distance themselves from him, including his main financial backer.