French President Nicolas Sarkozy's opinion poll ratings have come off rock-bottom as he and his likely left-wing challengers slow campaigning for next year's election during the country's annual August holiday. Barring emergencies, the summer lull gives the conservative leader, who began a Riviera vacation this week with first lady Carla Bruni, some space to consider his strategy before a two-round presidential election in April and May. He is widely expected to run for a second term but faces a tough battle, even after the exit of the former left-wing favorite Dominique Strauss-Kahn, who is fighting sex assault charges in the United States. Socialist Party grandees Francois Hollande and Martine Aubry are ahead of Sarkozy in most polls of voting intentions and the left is determined to win power after 17 years of conservative presidents. The Socialists will pick their candidate in October in a primary selection contest . A pre-campaign debate has begun on issues like the national debt, the cost of living, taxes and immigration.