President François Hollande, reeling from calamitous results in local elections, is expected to fire his Prime Minister tonight in attempt to give a new start to his stumbling presidency.
The change of government will be announced when Mr Hollande addresses the nation on on live television at 8pm French time (7pm BST). According to French TV news channels, Mr Hollande will announce that he has asked the energetic, ambitious interior minister, Manuel Valls, 52, to replace Jean-Marc Ayrault as Prime Minister.
Other appointments will be announced on Tuesday.
Ségolène Royal, Mr Hollande’s former partner, and the mother of his four children, is expected to return to national government as part of the reshuffle.
As the dust settled after the second round of municipal elections on Sunday, Mr Hollande’s Socialist Party found itself ejected from power in at least 140 cities and towns today . The centre-right Union pour un Mouvement Populaire (UMP) was the biggest winner but the far-right National Front consolidated its first round breakthrough and will take control of 11 towns nationwide.
Although most of these towns are small, this will give Marine Le Pen's anti-EU, anti-immigration, anti-free trade and pro-Russian party its biggest ever beach-head in local government. The previous high-water mark for NF control of town-halls was, briefly, four in the late 1990s.
Of the 11 new NF towns, only three are of any size, Fréjus and Béziers on the Mediterranean coast and Hénin-Beaumont in the industrial north.
FN candidates also triumphed in Mantes-la-Ville, west of Paris, Hayange and Villars-Cotterêts in the north and Beaucaire, Le Luc, Le Pontet and Cogolin in the South. The Far Right also won a "district town hall" in a racially-mixed northern part of the city of Marseille.
The Left hung onto power in several of France's largest cities - Lyon, Lille, Strasbourg, Nantes, Rennes and Dijon. It lost control of scores of others to the UMP, including the vibrant city of Toulouse in the south west and Caen in lower Normandy and a raft of towns traditionally run by the Left, including Belfort, Reims, Saint-Etienne, Roubaix, Quimper and Pau.
Swing voters and the middle classes have been angered by tax rises, especially the abolition of President Nicolas Sarkozy's "tax holiday" for overtime work. Poorer and left-wing voters have been infuriated by Mr Hollande's move in January to a more market-oriented, budget-cutting economic policy - even if it has not been implemented yet. Everyone is angry with Mr Hollande's failure to deliver his promised "reversal of the trend" of rising unemployment by the end of last year.
A change of Prime Minister will not mean another change of direction, the Elysée Palace insists. Mr Hollande is determined to push ahead with his new, more market-oriented - he prefers the phrase Social Democratic - approach to economic reform.
The new Prime Minister will, however, be expected to find some way of responding to the anger of the left-wing of the Socialist Party by devising tax breaks and other concessions for the less well off.