PARIS (AP) ― The leader of France’s resurgent, anti-immigrant far right, Marine Le Pen, said Tuesday she would not endorse either candidate in the country’s presidential runoff, a move likely to deprive President Nicolas Sarkozy of some sorely needed votes.

Le Pen, speaking at her National Front party’s traditional May Day rally, said she will cast a blank protest ballot on Sunday. She has set her sights are on June legislative elections. To her thousands of supporters, she said, “vote according to your conscience.’’

Le Pen assailed the conservative Sarkozy, who has borrowed some of Le Pen’s rhetoric about immigrants, Muslims and the inhuman face of Europe with its rules and regulations in his campaign, accusing him of impoverishing the French and giving up too much sovereignty to the European Union.

Polls have consistently suggested that Socialist candidate Francois Hollande will defeat Sarkozy in Sunday’s final vote. The incumbent, whose brash style has offended many French, is trying to win over the more than 6 million voters who supported Le Pen, who came in third in the first round vote April 22.

Le Pen’s score in the first round, nearly 18 percent, was the best ever by a candidate of the National Front, a party widely viewed as xenophobic. It propelled the party back onto the French political stage, where for decades Le Pen’s father, Jean-Marie Le Pen, had played the spoiler in elections. In the 2002 presidential vote, the elder Le Pen reached the final round, shocking France and the world.

“What effect does that have on you, my dear friends, to go from the role of idiot who votes for Marine Le Pen to that of arbiter in the presidential election?’’ she asked the crowd in front of the ornate Paris Opera house. “What effect does it have to go from the status of racist fascist and xenophobe to that of French with real concerns?’’

The National Front holds a May Day rally each year to honor Joan of Arc, the teen age warrior born 600 years ago who fought to oust the English from France. Le Pen laid a wreath at a gilded statue of Joan of Arc on the path of the march to the square in front of the Opera.

Across town, Sarkozy held a campaign rally of his own Tuesday where he reached out once again to the far right, evoking France’s Christian roots and a heritage that must be dearly guarded ― a theme dear to the National Front which fears that Muslim immigrants are intent on destroying old France.

In a radio interview Tuesday morning, Sarkozy was asked whether France has too many immigrants, and he answered, “yes.”

“Our system of integration doesn’t work. Why? Because before we were able to integrate those who were received on our territory, others arrived. Having taken in too many people, we paralyzed our system of integration,’’ he said on RMC radio.

“I will never argue for zero immigration, but the reality is that when you invite more people than you can handle, you no longer integrate them,’’ he said.

Le Pen threw cold water on Sarkozy’s attempts to woo her voters.

“I will cast a blank ballot,” she said. “Each one of you will make your choice,” she said, stressing that she could endorse neither Sarkozy nor Hollande ― but would not call on voters to abstain because the act of voting is “essential.”

Hollande is less in need of National Front support. He is assured of the backing of voters who gave extreme-leftist Jean-Luc Melenchon 10 percent in the first round. Still, Hollande is quietly looking for National Front votes he says were cast in anger at the establishment.

At a speech Tuesday in Nevers, in the Burgundy region, Hollande said “we cannot welcome foreigners when our economic situation doesn’t allow us to.’’ In an evening interview on France-3 TV, he said he wasn’t out to seduce “this or that voter” but looks to “all voters, and notably the most desperate.”

For Le Pen, the real election is the June legislative vote when she hopes to put lawmakers in parliament. The National Front had 33 lawmakers in the lower house until 1986, when voting rules changed.

“It is not the president who will be elected (on Sunday) but a simple employee of the European Central Bank,” said the woman who bills herself as the “anti-system” candidate.

Le Pen has said in the past that her goal is to “explode” the right and become the main opposition under a Socialist president. Sarkozy’s Union for a Popular Movement party, or UMP, which combines various right-wing tendencies, is already showing signs of stress as he pitches to the far right.

A 43-year-old National Front supporter pushing his infant son in a stroller along the march path said he will vote for Sarkozy on Sunday.

It won’t be easy because “Sarkozy lied to us for five years,” said Jean-Charles Laffitte. But it is “just to keep the left from winning.”

Another National Front supporter, Philippe Nelson, 36, said he’ll cast his ballot for Hollande. “Nicolas Sarkozy, I want him out once and for all,’’ he said.