Paris - Socialist Segolene Royal warned on Friday that France could slide into violence if Nicolas Sarkozy wins the presidency as polls showed the rightwinger had extended his lead.

"His candidacy is dangerous. That is why I ask voters to think twice," said Royal in an interview to RTL radio on the final day of campaigning ahead of the election on Sunday.

Two polls released on Friday showed Sarkozy pulling ahead of Royal with 53 and 54% of votes against 46 and 47% for the Socialist.

Royal, who wants to become France's first woman president, said she was "issuing an alert" that the election of Sarkozy to the presidency could "trigger violence and brutalities across the country".

She described her rival as "the candidate of the hard right" and said his victory would create "very strong tensions in the country".

Sarkozy reacted to Royal's attacks by saying that she was upset by her drop in the polls.

'She is getting tense'

"It must be the polls. It's so outrageous," Sarkozy said of her comments in an interview to Europe1 radio. "She is getting tense, stiffer because she feels the ground shifting."

Sarkozy, the former interior minister, is hated by many on the left and in the high-immigrant suburbs for his tough-talk on immigration and law and order.

His description of young delinquents in the suburbs as "rabble" ahead of the 2005 riots made him an enemy of the Arab and African residents of the poor areas surrounding Paris and other major cities.

Royal noted that Sarkozy had not been able to campaign freely in the suburbs without the escort of "hundreds of police".

She also accused him of having ties to media and financial interests, reiterating that his candidacy was "dangerous in terms of the concentration of powers, in terms of brutality and in terms of lies".

"I am not a woman of a clique," she said, adding that she was ready to reach out to the centrist voters.

Nearly seven million voters who backed centrist Francois Bayrou in the April 22 first round of the election have been courted assiduously by both Royal and Sarkozy ahead of the runoff.