From London to Moscow, and from Paris to Athens, Europeans are marking May Day, the traditional workers' holiday. The biggest demonstrations were held in France, where more than one million people took advantage of the holiday to stage protest marches against extreme right-wing presidential candidate Jean-Marie Le Pen.

It was a sign that French voters have emerged from the apathy that marked the presidential campaign before Mr. Le Pen shocked the nation by qualifying for Sunday's run-off election against incumbent Jacques Chirac.

Massive demonstrations in Paris and in provincial cities roared their disapproval of the controversial anti-immigrant politician. Marchers called him a Nazi and a Fascist and vowed to defend the values of liberty, equality, and fraternity enshrined in France's 1789 Revolution.

Earlier, Mr. Le Pen staged his own march through Paris. Police said eight to 10,000 pro-Le Pen demonstrators showed up, but the candidate's National Front party claimed that 100,000 took part.

In a speech to his supporters, Mr. Le Pen railed against immigration, reaffirmed his intention to pull France out of the European Union and the euro single currency, and accused Mr. Chirac of being what he called the godfather of corruption in France.

So far, the anti-Le Pen marches have been peaceful, but police are worried that, if they turn violent, given the intensity of feeling against Mr. Le Pen, they could play into the right-wing leader's hands.

In Britain, meanwhile, up to 10,000 anti-capitalist and environmentalist protesters descended on central London. More than 100 demonstrators on bicycles blocked intersections along Oxford Street, a busy shopping area. But the demonstrations were largely good-natured.

That was not the case in Berlin, where 83 policemen were injured during a night of clashes with anarchists on the eve of May Day. The anarchists threw rocks, set street fires, and looted a supermarket. Police say they fear more violence before the day is over and are out in force in the German capital's streets.

In Moscow, about 150,000 people took part in marches and rallies to mark May Day, which used to be one of the most important holidays in Soviet times, but appears to have lost much of its meaning since then. Trade union members holding up pictures of Russian President Vladimir Putin staged one demonstration. The Communists staged another, with mostly elderly people lamenting what they say is the decline in living standards since the fall of Communism.

Italian trade unions held their biggest rally of the day in the city of Bologna, where they protested a plan by Prime Minister Silvio Berlusconi to make it easier for firms to fire workers.

In Athens, demonstrators marched to the U.S. and Israeli embassies to express support for the Palestinian struggle against Israel.

May Day demonstrations were held in other capitals, but most Europeans are simply taking the day off, using the occasion to visit friends or relatives or spend some time at home.