Is the French left ready to be led by an openly gay politician?

A new star is rising on the French Left, propelled by pedal power, loathing of Ségolène Royal and the conviction that the French love affair with Nicolas Sarkozy cannot last.

Bertrand Delanoë, 56, the popular mayor of Paris, has the small matter of his own re-election to contend with next Spring. No matter. His friends and allies are convinced that only he can rescue the divided and quarrelsome Parti Socialiste from a permanent takeover by the defeated but unbowed presidential candidate, Mme Royal.

M. Delanoë made the first, clear statement of his own national ambitions this week with a biting attack on both Mme Royal and President Sarkozy in an article in Le Monde before the Socialist party summer school opens in La Rochelle tomorrow.

He accused Mme Royal's failed election campaign of being a triumph of "marketing" over "substance and values" and even over "ethics". He dismissed the recent history of the Parti Socialiste as a "soap opera". This was also a thinly disguised attack on the party leader, François Hollande, whose romantic split with Mme Royal after a 25-year unmarried partnership has dominated the post-election manoeuvring on the Left.

There is no doubting M. Delanoë's ability or his high reputation in Paris as an innovative, tax-payer-friendly politician. His popularity has been boosted in recent weeks by the immense success of a cheap, self-service bicycle scheme, which has transformed Paris into a kind of Gallic Amsterdam.

However, one largely unspoken shadow hangs over M. Delanoë's ambitions. The mayor of Paris is the only high-profile politician in France to have declared his homosexuality. In cosmopolitan Paris, this is not an electoral handicap. The same is not true in La France Profonde.

A senior provincial figure in the Parti Socialiste, (and a Mme Royal supporter) told The Independent yesterday: "Being mayor of Paris is already a drawback in some parts of the provinces. Being a homosexual mayor of Paris, well, it just doesn't wash, not with party activists and certainly not with the mass of the electorate.

"France may or may not have been ready to elect a woman as President. Unfortunate though it may seem in the early 21st century, France is not yet ready to contemplate a gay President."

The French mainstream media prefers not to address the issue. The usually outspoken, centre-left newspaper, Libération, devoted its first three pages to M. Delanoë yesterday without raising the question of whether his homosexuality makes his national ambitions doomed to failure.

In an opinion poll last week only seven per cent of those questioned identified M. Delanoë as the most likely person to restore the fortunes of the French Left. Mme Royal remains the popular choice with Socialist party members. The wider electorate prefers the former finance minister, Dominique Strauss-Kahn, who may leave French politics shortly to become head of the International Monetary Fund in Washington.

M. Delanoë's supporters admit that he has an "image deficit" within the wider Socialist party. They believe that this can be repaired if he is overwhelmingly re-elected as mayor of Paris next March. One Parisian socialist politician says: "He is careful and doesn't want to burn his wings. But he is starting to build a movement within the party, based on a hard core of ex-Jospinistes (supporters of the former prime minister, Lionel Jospin)."

"Mme Royal remains his obsession and his chief target."

In six years as mayor of Paris, M. Delanoë, has built a reputation as a practical, imaginative politician. He has, on the whole, delivered his promises to make the capital a greener place, friendlier to poorer residents, without soaking richer tax-payers.

His Vélib scheme, which has put a rank of self-service, cheap bikes on almost every street corner, is a classic Delanoë operation. The cost to bike-users is minimal for short hires. The cost to the tax-payer is zero. The service is subsidised by the J C Decaux street amenities company in return for scores of new advertising sites in the capital.

Delanoë supporters say that this is typical of the new thinking that he is prepared to bring to national politics. He is not afraid of partnerships with private enterprise but he keeps clear social and environmental goals in mind.

In some ways – sexual orientation apart – M. Delanoë resembles the new Socialist leader across the Channel, Gordon Brown. Both are austere, acerbic men, more interested in results than "spin" or marketing.

A triumph for M. Delanoë in the town hall elections next March seems likely. The Parisian centre-right is, as ever, split.

In any case, President Sarkozy does not regard the unseating of M. Delanoë as a priority. Rightly or wrongly, the new President does not regard the Mayor of Paris as a serious threat in the presidential election of 2012.