Jean-Francois Cope, leader of the Union for a Popular Movement (UMP), on Tuesday urged French voters not to vote for the National Front in the forthcoming parliamentary elections.

"I say to the French who want to vote to the National Front that by voting for the National Front, it's the left that will win," Cope was quoted by French RTL radio.

"So, I invite you to be very, very, very careful because this vote for a parliamentary vote is crucial to the future of our country," he added.

On Monday, the official campaign for two rounds of legislative elections kicked off, launching a fierce battle between the left that wants to win a majority to bolster its May 6 general elections victory, and the right that hopes to snatch enough seats in the National Assembly to block Socialists' reforms.

"Now, it is time to mobilize for parliamentary elections. It is not good to give all power to one political party, to the left," Cope said in a previous televised interview.

Opinion polls show that the Socialists and other left-wing parties could garner up to 46 percent of the vote in the first round of the election on June 10, trouncing UMP's projection of 32.5 percent.

According to the interior ministry, 6,611 candidates will compete for the National Assembly's 577 seats. Candidates need to gain at least 12.5 percent of the first-round votes if they are to enter the second round scheduled for June 17.