The leader of France's governing UMP party, Nicolas Sarkozy, has called for a break with the past in a keynote speech to young party activists.
Young people can change the world, Mr Sarkozy said
His speech, widely seen as the start of his bid for the presidency, centred on the theme of young people who he said had always shaped France's destiny.
Mr Sarkozy, currently interior minister, promised a nation where those who worked hard would be rewarded.
He is hoping to be the UMP's candidate in next April's presidential election.
Mr Sarkozy's speech was greeted by tumultuous applause from the young UMP activists in Marseille, who had already given the conference the air of a rock concert.
The young, he said, had always shaped France's destiny from the French Revolution to the French resistance during World War ll.
"Yes, young people of France, everything is possible," he said.
"Everything is possible if you want it. And here in Marseille, I have come to say to you that we want it more than ever before... more than anyone has ever wanted. That is my message to the youth of France."
Correspondents say his speech aimed to win over sceptical younger voters who were alienated by his tough stance during urban riots in France late last year.
Among a raft of proposals, he outlined plans for interest-free loans for student entrepreneurs, special education savings accounts, and "second-chance schools" for troubled students.
He had a direct message for young people from ethnic minorities, saying they should not forget their origins but be proud of France and its heritage.
He also called for a six-month obligatory community service for 18-to 30-year-olds.
"There is no nation without obligations of individuals" to the nation as a whole, Mr Sarkozy said.
The UMP leadership was keen to present a united face
He criticised the 35-hour working week introduced by the Socialists, and said he wanted to create a nation in which those who worked harder would earn more, one in which effort would be properly rewarded and where wealth would create more wealth for France.
Mr Sarkozy did not once mention President Jacques Chirac, who has been in power for a decade and in whose cabinet he serves.
This was undoubtedly the start of Mr Sarkozy's campaign to win the party nomination as candidate for president, the BBC's Caroline Wyatt reports from Marseille.
His main rival, Prime Minister Dominique de Villepin, emphasised the need for party unity in an opening speech at the conference on Friday.
"This is my pledge - our [political] family will be united for the major elections of next year," he said to applause, in a speech which also emphasised recent government progress in tackling unemployment.
Le Pen vote
From the enthusiastic reception for Mr Sarkozy's speech, it is clear that the young party members firmly back the UMP leader as their best hope of reforming a creaky French state, our correspondent says.
But although Mr Sarkozy is the clear frontrunner for the conservative nomination, he divides opinion even within UMP ranks.
"He has charisma," one young activist told the BBC. "He makes things happen."
Another said Mr Sarkozy represented a new generation, a change from the old political guard represented by President Chirac.
But Mr Sarkozy has been accused by some of veering too far to the right politically, for example by being tough on immigration and crime in his role as interior minister.
However, his supporters see that as the only way to fend off the popularity of Jean-Marie Le Pen's far-right National Front and try to ensure that Mr Le Pen does not get through the first round of next year's elections, as he did in 2002, our correspondent says.