Supporters of France’s National Front look set to be the kingmakers in deciding who becomes the country’s next leader.
The far-right party picked up its best-ever result, with nearly one-fifth of ballots cast.
But aides close to leader Marine Le Pen say that she has no intention of endorsing Sarkozy’s UMP party.
“What we can see tonight is the great cacophony between the left and right. At the legislative elections, the French will have a definitive choice of a new right,” said Louis Aliot, National Front vice-president and Le Pen’s partner, of June’s parliamentary elections.
Sarkozy is likely to talk up issues such as immigration and crime in a bid to attract National Front supporters in the next round of the presidential vote.
Leftist candidate Jean-Luc Melenchon told a post-vote rally that they must unite together on May 6 to beat the incumbent president, without mentioning Hollande by name.
Socialist contender Hollande has already received the endorsement of Green candidate Eva Joly.
Opinion polls hand Hollande a comfortable victory in the second round. Many of the editorials in Monday’s press read like Nicolas Sarkozy’s political obituary.