Conservative French President Nicolas Sarkozy has caught up with his Socialist challenger in the first round of a presidential election next month and is whittling away his strong lead for the runoff in May, three polls showed on Tuesday. An IPSOS Logica poll found Francois Hollande, vying to be France's first Socialist president since 1995, would win 28 percent of the vote in the April 22 first round, narrowly ahead of Sarkozy's 27.5 percent. The poll, conducted at the end of last week shortly after police shot dead a militant gunman who had killed seven people, showed Hollande had shed half a percentage point in a week while Sarkozy had held his ground. However, it showed Hollande still beating Sarkozy in the May 6 runoff by 54 percent to 46 percent, although the president had narrowed the margin to eight points from 12. A Harris Interactive poll showed Sarkozy overtaking Hollande in the first round, giving him 28 percent of the vote to 27. It also showed Sarkozy had cut Hollande's lead in the runoff to eight points at 54-46 percent. A separate daily Ifop-Fiducial poll, which has already seen Sarkozy leapfrog Hollande in the first round earlier this month, showed the president slightly widening his first-round lead to 28.5 against 26.5 percent. It showed Hollande's lead in the runoff had fallen to seven points with the Socialist candidate at 53.5 percent and Sarkozy at 46.5 percent. All three surveys showed hard-left candidate Jean-Luc Melenchon making strong gains, overtaking centrist Francois Bayrou.