French President Nicolas Sarkozy has reshuffled his cabinet after a heavy defeat for his party in regional polls.
Labour Minister Xavier Darcos has been replaced by Budget Minister Eric Woerth, whose place is being taken by Francois Baroin.
The poll has left President Sarkozy's centre-right UMP party in control of just one of the 22 regions in mainland France and Corsica.
Mr Sarkozy has suggested he may slow the pace of unpopular reforms.
'Wake up call'
More from Emma Jane Kirby
Mr Gueant described the result as "a big wake-up call for quick and effective action" on unemployment and other economic challenges, while Mr Fillon said the vote showed that the centre-right had not been "convincing".
Opposition leader Martine Aubry said the results expressed the French people's "rejection of the politics of the president and the government".
One poll has suggested that 57% of people would like to see a change of government after the regional polls.
The poor results may make Mr Sarkozy far more cautious about pushing through a comprehensive programme of reforms that has already clearly cost him votes, the BBC's Emma Jane Kirby reports from Paris.
Strike action
Many people are angry that the president's election promises - to make ordinary people richer and to make France more competitive - have failed to come good, our correspondent says.
High unemployment and resentment over planned judicial and pension reforms are among the factors seen to have prompted people to use regional elections to punish the central government.
With three million people currently out of work, France is now suffering its highest level of unemployment in decades.
Mr Sarkozy faces a reminder of the challenges ahead on Tuesday, with public sector workers due to strike over the pension reforms, working conditions and spending power.
Following the regional elections, the centre-right holds only the right-wing stronghold of Alsace among the 22 regions in mainland France and Corsica. It lost control of Corsica in the poll.
The elections also saw a reversal of the decline of the far-right National Front, which won more than 9% over two rounds of voting.
