The left claimed an historic victory in Paris in municipal elections that punished the right in France's capital but voters dealt Prime Minister Lionel Jospin's Socialists a string of defeats in the provinces.
France's second city Lyon was also set to shift left after yesterday's run-offs one year before presidential and legislative elections.
Mr Jospin is then expected to challenge conservative incumbent Jacques Chirac for the nation's highest office.
Almost 30 towns turned right. Some of Mr Jospin's key ministers tumbled to embarrassing defeats in their quests for second jobs as mayor.
Mr Jospin said: "This is a good local result in Paris, it is a good local result in Lyon, and then we have also had some failures which we are going to have to think about."
He went to congratulate his friend Mr Bertrand Delanoe for winning Paris.
Tens of thousands of joyous leftists thronged the square outside Paris City Hall near the Seine after pollsters projected victory for Mr Delanoe, one of France's few openly gay politicians, over a feuding right.
Final results gave the unassuming 50-year-old senator's alliance 92 of the 163 seats on the Paris council to put the left in control of the city for the first time since the 1871 Paris Commune.
Mr Philippe Seguin, official candidate of Mr Chirac's RPR party, took 55 seats, with 13 going to the scandal-tainted outgoing mayor Mr Jean Tiberi and three to other right-wing forces.
The result marked a personal blow for MrChirac, who served as mayor for 18 years until his election as president in 1995. He has treated the capital as his personal fiefdom for close to a quarter of a century.