Greens and ex-Red fail to gel in France's newest political party

France will gain a new political party this weekend which could, it believes, instantly become an important player in the country's future.

The party is, in theory, neither left nor right but green, with blue and yellow tendencies. In the best traditions of French politics, it shows signs of splitting into mutually-detesting factions even before it is formally created by an inaugural conference in Lyons today.

Its presidential candidate at the next election in 2012 is likely to be a 66-year- old woman who came to France as a au pair from Norway and still speaks with a Scandinavian accent. Is this, therefore, a joke, or marginal, party? Not at all. The party, which has not yet chosen its name, has already proved to be a powerful electoral force in the last two nationwide polls. Les Verts-Europe Ecologie, its provisional name, could play a decisive role in the presidential election in 2012 and could provide a model for a looser, more voter-friendly political movement for the 21st century.

Les Verts-Europe Ecologie is a merger between the French Green Party and a wider, pro-European, ecological movement created for the 2009 European elections by Daniel Cohn-Bendit, the Franco-German Euro MP and leader of the student revolt of May 1968.

The two movements have formed a successful electoral alliance for two years, taking 16.3 per cent of the vote in the European elections in 2009 and 12.5 per cent in regional elections in March this year. At Mr Cohn-Bendit's suggestion, they will now become one party – but that has not prevented an outbreak of name-calling between leading ex-Greens and the former Red.

In its manifesto, the party says that the arguments of left and right are now defunct. The future will be "shaped by the spectre of an unprecedented, historic event, a simultaneous and brutal ecological, economic and social collapse".

Despite this apocalyptic statement, Mr Cohn-Bendit fears that some of the ex-Green leaders in the new movement are still broadly leftist in outlook. He also accuses them of harbouring anti-European attitudes.

Mr Cohn-Bendit suspects that the old Green leadership wants to create a "tribal", inward-looking and careerist party, in the image of the old "Verts". He believes that the movement should become the model for a new kind of "political cooperative", with loose "associate" supporters as well as formal members.

The leader of the old Verts party, Cécile Duflot, has branded Mr Cohn-Bendit a "grumpy smurf". She suggested this week that he remained a permanent rebel who could not bear to belong to any movement – even one he founded.

Fortunately, given these divisions, the party has all but designated its presidential candidate for 2012. Eva Joly came to France in 1961 and rose to become one of the country's most feared investigative magistrates. Although a well-known name, many doubt that she has the ability to be a successful politician. The problem, they say, is her tendency to lecture audiences in a dry monotone.

In a rare flash of humour this week, Ms Joly described herself as an ageing woman with a strong accent, who wanted to be a candidate against "menopause discrimination" and the "excessive consumption" forced on the young.