French police held several topless activists from the radical feminist group Femen who attempted to storm a traditional march held by the far-right National Front (FN) party to pay tribute to Joan of Arc on May Day.
Up to four bare-chested "sextremists" - as Femen calls its members - tried to block the way to the parade captained by FN's leader Marine Le Pen and her father, Jean-Marie, as it was about to set off from the Palais-Royal palace in central Paris.
The activists, who had daubed FN's logo and the slogans "Fascist epidemic" and "Stop the Fascist Union" across their chests, were carried away by police.
"We will not allow Europe to become a Fascist union. Stop the epidemic," the feminist group tweeted from its French account.
A couple of hours later, another Femen member was restrained by security personnel, as she attempted to disrupt Le Pen's speech in Place de l'Opéra, where FN's march ended.
From the stage, Le Pen, urged thousands of supporters to vote at the EU elections on 22-25 May to "say no, once again, to this European madness".
Le Pen claimed that the EU represents a threat to France's national identity and culture and thus has to be dissolved.
"Nothing differentiates a Frenchmen from a German or a Romanian anymore," she contended.
"France must remain France and its people must remain French," Le Pen charged. "It's not enough to have some papers to be a Frenchmen."
On the way to Place de l'Opéra, the parade stopped to pay respect at the foot of the Joan of Arc statue in the Place des Pyramides.
The mediaeval heroine is revered as a nationalist icon by FN supporters who say her fight against English occupation in the 15th century symbolises France's resistance against all foreign invaders, today represented, in their eyes, by immigrants and Brussels.
Joan of Arc is usually celebrated on 8 May, the date marking the liberation of Orleans. In 1988, however then-FN leader Jean-Marie Le Pen decided it was convenient to the party to hold the tribute rally on 1 May in conjunction with International Workers' Day, a national holiday in France.
FN is polling at more than 30% nationwide and is expected to score a historic result at the EU elections.