right leader Marine Le Pen in the first round of France's presidential election has lifted Nicolas Sarkozy's hopes of clinching a second term, but he will struggle to win over enough of her voters to keep him in power. Surveys show fewer National Front voters will rally behind the conservative Sarkozy in a runoff vote than did in the 2007 election, and as he shifts further rightwards on immigration and Europe he risks alienating the centrist voters he also needs. Socialist Francois Hollande beat Sarkozy in Sunday's first round by 28.6 percent to 27.1 percent, but Le Pen stole the show with a 17.9 percent score, the biggest tally a far-right candidate has ever managed. The nearly one in five who voted for her will be key for the runoff between Sarkozy and Hollande, but political analysts see the incumbent's ability to woo them limited by his European commitments and his need to keep centrists on board. “It will be very difficult for Sarkozy to gather votes from both the National Front and the center at the same time,” said political scientist Jean-Yves Camus, an expert on the far right. Le Pen called in her campaign for France to quit the euro currency and free itself from the ties of European economic policy. The message appealed to low-paid workers, the jobless and anxious young whites fed up with rife unemployment and calls for more austerity which they blame on European integration. Camus said Sarkozy's strategy of raising red-flag issues such as Islam and immigration to appeal to far-right voters was having limited effect with people who want France out of the euro single currency. Sarkozy has already gone a long way with campaign pledges to halve immigration and pull France out of Europe's open-border Schengen zone unless external frontiers are strengthened. But given his responsibilities as head of Europe's No. 2 economy, he would struggle to tell Le Pen voters what they want to hear on Europe. “People are worried more today about the economic crisis, unemployment and purchasing power than immigration. Le Pen voters want the end of the euro and Europe and they know Sarkozy is attached to those things, and to economic liberalism,” Camus said. Agriculture Minister Bruno Le Maire, who has worked on Sarkozy's campaign, told Le Monde daily that it would be key for the second round to stick to a consistent line, and not try to target some pledges at the far right and others at the center. “If we want to convince far-right voters, we mustn't be offering them winks and nudges, we must show them that we are unbending on the values we defend,” he said. The 2012 election has been seen as a referendum on Sarkozy's unpopular presidential style and his failure to bring down high unemployment as he promised during his 2007 campaign. Opinion polls for the May 6 runoff show him 6-12 points behind Hollande, but analysts now see a much closer finish. Sarkozy would need around 80 percent of Le Pen voters behind him to avoid defeat, according to analyst estimates and a Reuters calculator. But surveys conducted during or after Sunday's first-round presidential vote found that between only 44 percent and 60 percent of Le Pen voters plan to switch to Sarkozy in round two. With the far-left pulling behind Hollande, the only other large pool of voters up for grabs are supporters of centrist Francois Bayrou, who received 9.1 percent of the first round vote. Polls show them splitting in the second round. One-third of Le Pen voters are expected to stay at home on May 6, so Sarkozy is looking at a much lower transfer of votes than in 2007, when 70 percent of far-right and 50 percent of centrist voters switched to him. “To clinch it, he would need three-quarters of Le Pen votes and two-thirds of Bayrou votes, whereas he's looking at around half of Le Pen's voters and a third of Bayrou's,” said analyst Frederic Dabi at pollster Ifop. “The arithmetic is far from being right for Sarkozy.” Neither Bayrou nor Le Pen has yet called their supporters to back one or other candidate for the runoff. With her eyes on a strong showing for the National Front in June parliamentary elections, Le Pen is keeping her distance from Sarkozy. National Front Vice-President Louis Alliot suggested Le Pen would not endorse either candidate. “Based on the ideas in our program, neither one defends or develops them, so it seems unlikely,” he said. Hard leftist Jean-Luc Melenchon, who won 11 percent in the first round, is endorsing Hollande, and polls show at least 80 percent of his supporters will vote Socialist on May 6. An Ipsos poll found 60 percent of Le Pen voters and 32 percent of Bayrou voters would back Sarkozy on May 6, while a Harris Interactive survey found 32 percent of Bayrou voters and only 44 percent of Le Pen voters switching to him. “If this is what we see in two weeks' time, Nicolas Sarkozy is finished,” said political analyst Roland Cayrol.“To get 80 percent of Le Pen voters and two-thirds of Bayrou's is not at all what's in the opinion polls. It's not impossible but it would be remarkable,” he said. Sarkozy responded to Le Pen's record showing by immediately promising a greater focus on tightening border controls and stopping factories leaving France. On Monday, he hammered home pledges to get tough on immigration and crime. “National Front voters must be respected,” he told reporters as he left his campaign headquarters in Paris. “They voiced their view. It was a vote of suffering, a crisis vote. Why insult them? I have heard Hollande criticising them.” __