Ségolène Royal, long the popular favourite, moved a step closer yesterday to being the French Socialist Party’s nominee for next year’s presidential election. Party members will vote next month to choose their candidate, but already the field has narrowed to just three.

Royal got some publicity in our part of the world over the weekend with the allegation that her brother was involved in the bombing of the Rainbow Warrior in 1985. More significant, however, is the fact that one of the world’s most tradition-bound left-wing parties is about make a dramatic break with tradition.

Less than three weeks ago, as Le Monde reports, there were seven hopefuls for the Socialist nomination. But most of them, including former prime minister Lionel Jospin and party secretary François Hollande, have apparently decided that Royal is unbeatable. Hollande told Le Figaro that his decision was “not linked to persons, but to context”, but it was surely not irrelevant that Royal is his de facto wife.

The other two candidates remaining are Laurent Fabius, also a former prime minister, who appeals to the party’s left wing, and Dominique Strauss-Kahn, a centrist and former economy minister. Both will be trying to stress Royal’s comparative lack of experience, but neither is given much chance of overtaking her.

Her major appeal to Socialist members is that she offers the chance of victory, and for a party that hasn’t held the presidency since 1995 that seems to be the main consideration: doctrinal purity is going to take second place.

Royal’s popularity comes not just from her glamour, but also from the fact that many French see her as able to break with tradition where necessary – including the traditions of her own party. Back in April, a poll in Le Figaro found 59% had confidence in her ability “to take the economic reforms that France needs” – more than any other prospective candidate, and ten points ahead of the likely centre-right candidate, Nicolas Sarkozy.

For a party whose public face has so often been set against any sort of economic reform, Royal could be a breath of fresh air. Time will tell whether she has substance as well as style.