Royal, the socialist, is tipped as France's first female president

The former cabinet minister Ségolène Royal has begun to outdistance all other potential candidates for the centre-left in the next French presidential election.

Mme Royal, 52, although dismissed by many as a lightweight, is now a strong contender to become the first woman presidential candidate for a leading French political party.

A series of recent polls has placed her far ahead of other potential centre-left candidates in 2007, including her partner, François Hollande, the leader of the Socialist party.

Whether Mme Royal, president of the Poitou-Charente region, is capable of becoming France's first "presidente" remains uncertain. Even friends within the Parti Socialiste suggest she has nothing much to contribute on " big questions", such as the economy and international affairs.

To counter this impression, Mme Royal will this week launch a think-tank and pressure group called Désirs d'avenir (future desires). This is seen as a first step towards creating a formal "Ségolène for President" campaign before the Socialists choose their candidate next October. In an interview with the magazine Le Nouvel Observateur, Mme Royal said that she was "ready" to run for the presidency if the tide of popular opinion continues to run in her favour.

"If this trend persists, which I believe it will, and if left-wing electors ask for me, which I hope that they do, then I will emerge naturally [as the party candidate]," she said. "The others will have no choice. It will be me!" As if conscious that this sounded rather presumptuous, she rapidly added that she would willingly bow out of the race - "without feeling that my life is ruined" - if a stronger candidate emerged.

In the latest opinion survey at the weekend, conducted by CSA for the Journal du Dimanche, Mme Royal was chosen by 36 per cent of those polled as the best candidate of the left.

The former prime minister, Lionel Jospin, a failed presidential candidate in 2002, scored 26 per cent - but he has insisted that he will not run again.

Those who have declared an interest, or are presumed to be interested, trailed far behind Mme Royal. The former culture and education minister, Jack Lang, scored only 18 per cent, the former finance minister, Dominique Strauss-Kahn 17 per cent, M. Hollande 12 per cent and the former prime minister, Laurent Fabius, 12 per cent.

Although there are still many months before the campaign proper begins, political pundits and party insiders who initially dismissed Mme Royal's chances are having to think again. The Socialist party spokesman, Julien Dray - a friend of both Mme Royal and M. Hollande - said: "Something is beginning to happen for Ségolène, it's undeniable."

Mme Royal is an excellent television performer who takes a conservative line on some social issues and a more interventionist, socialist line on economic problems. She has benefited in part from the "Merkel effect". The installation of the first woman Chancellor of Germany has helped to lower the psychological barrier to a woman challenging for the presidency of France.

Mme Royal also seems to have benefited from the uncertain mood of a French electorate, which is desperate to see new faces in power but not necessarily ready for an abrupt change in political direction.

The more cynical barons within the Socialist party suggest that Mme Royal is popular because she is superficially different from the tedious and familiar male faces but offers no threat to the status quo.

They suggest that these advantages are likely to fade and vanish as the election, in May 2007, draws nearer.

Despite much speculation, the mood within the Hollande-Royal household remains unclear. The couple have lived together for 20 years. They have four children but have never married, by her choice.

M. Hollande has said that he will support his "wife" willingly if she emerges as the strongest candidate. Friends hint that he is astonished, and a little miffed, by his partner's new popularity. Enemies within the party insist that Mme Royal's rise has been carefully choreographed by the couple to block other candidates.