By Nicholas Vinocur
PARIS (Reuters) - A new French centrist alliance was launched on Tuesday aimed at taking votes from left and right to build a strong foothold in the European Parliament next year, capitalizing on frustration with President Francois Hollande.
The alliance, to be called The Alternative, brings together rival veterans of centrist politics Francois Bayrou and Jean-Louis Borloo, who split in 2012 when the former endorsed the Socialist Hollande and the latter conservative Nicolas Sarkozy.
With a limited political footprint - just 72 mayors among thousands in towns of more than 10,000 - the new group may struggle to gain ground in municipal elections in March against locally established mainstream parties, analysts say.
But its chances may be better in the European election in May, when the centrists' resolutely pro-EU outlook will contrast with their broadly euro-skeptic opponents.
"There is room for a pro-European message, which is at the heart of the centrist brand," said Jerome Fourquet, an analyst at pollster Ifop. "But the European dream is broken... They will need to have strong proposals, like pushing integration further for core euro zone members."
Polls show Hollande's Socialist Party losing ground in both elections as frustration over unemployment above 11 percent, economic stagnation and immigration drives more voters toward Marine Le Pen's far-right National Front party.
An Ifop poll last month showed the National Front winning more seats in the European Parliament than any other French party, and more than twice as many votes as the nascent centrist alliance of the Modem and UDI centrist parties.
At Borloo's insistence, The Alternative's founding charter says the movement considers itself in opposition to the ruling Socialists at the national and local levels, and calls the "republican right" its natural partner.
It may draw some moderate conservatives dismayed by the main Gaullist UMP opposition party's lurch to the right on immigration and crime issues to try to win back voters from the National Front, but critics say the alliance may struggle to attract much support from the left.
Borloo and Bayrou say their alliance could recreate a powerful centrist movement similar to the defunct UDF, created to support then-President Valery Giscard d'Estaing in 1978.
But France's two-round electoral system makes it hard for an independent centrist force to achieve a breakthrough alone.
Seeking to cement their center-right stance, Borloo and Bayrou have sharpened attacks on Hollande. Bayrou, who was shunned by the right but not rewarded by the left for backing Hollande, accused him of "losing control" over his cabinet in a scandal over the expulsion of a Roma teenager last month.
Sarkozy supporters still view Bayrou, who scored 9 percent in his third presidential bid last year before choosing Hollande, as a traitor who cost their hero his re-election.
Borloo and Bayrou may yet fall out over the 2017 presidential election, for which the new alliance says it will nominate a candidate by an unspecified democratic process.
"This is not a party," Alba Ventura, a political commentator, said on RTL radio. "It's a civil union, a wedding, an Italian-style political coalition."
Even so, Fourquet said that if Borloo and Bayrou could deliver an original message on Europe, they could achieve a surprise in the European poll, noting that the pro-European Greens won a bumper 16.3 percent in the 2009 European election, almost level with the Socialist party.
(Editing by Paul Taylor and Alistair Lyon)