Segolene Royal officially announced her intention to stand last Friday. And now the man many consider will be her main opponent, Bertrand Delano?, has released a book ?De l'audace? in which he sets out his vision for the future of the party and also takes aim at Royal.

When she announced her intention to stand, the party's old guard or so-called ?elephants? ? many of whom have been at the helm for a very long time and openly support Delano? - were quick to criticise, saying Royal's move would only further serve to split an already divided party and that she had declared herself too early.

They also accused her of ignoring party rules ? even though she was by no means the first or the only one to have announced her candidature ? and prematurely sparking a likely (media) confrontation with Delano?. In reality her choice of timing was probably made to help take the sting out of the publication of Delano??s the book.

And in a sense the release of ?De l'audace? is a rather disingenuous move by Delano?, who in March won re-election for a second term as mayor of Paris.

He still hasn't officially declared himself as a candidate to head the party, even though everyone expects him to stand. Instead up until now he has allowed many of the ?elephants? to do his bidding, and especially his mentor and main backer, the former prime minister, Lionel Jospin.

While recognising that the Socialist party has been in something of a malaise for several years, Delano? insists (in his book) that the party didn't do itself any favours in choosing Royal as its candidate in last year's presidential elections.

In levelling such criticism Delano? is firmly aligning himself with those that many (including Royal) say were responsible for the decline in the fortunes of the Socialist party.

Delano? accuses her of having run a directionless campaign and he firmly rejects any sort of alliance with MoDem, the centre party. Anyone even slightly familiar with French politics will recognise the words as ones echoing those of Jospin in his book, which attacked Royal last year.

In terms of policy perhaps the most surprising element of Delano??s book is his call for the Socialist party to embrace economic liberalism and to accept the principle of competition ? long a taboo to many on the Left. Indeed Delano? proudly claims to be a ?liberal? himself in the true humanitarian sense of the word of course, and insists that it has long been a principle abused and misused by the centre-right.

The release of the book then is in effect just the latest offensive in a campaign, which gives Delano? national exposure without requiring him to take the plunge and officially declaring himself to be in the running for either November's battle for leadership of the party or more importantly nomination as its candidate in the 2012 presidential race.

For her part, Royal has admitted to mistakes made in last year's presidential elections and said she wasn't helped by the lack of real support she received from the party's ?elephants?. She believes in realigning the party with the centre and in the more populist ?listening and hearing? approach to politics. In addition she has already made clear that for her, the leader of the party should also be the 2012 presidential candidate.

Other major differences between the two pretenders to the Socialist ?throne? will become clearer once they have both officially declared.

For the moment though the knives are out and all the current incumbent, Royal's former partner, Fran?ois Hollande, can do is look on from the sidelines and keep his fingers crossed that the two don't go for each other's jugulars over the coming months.

A very public display of infighting is the very last thing the party can afford, especially after it has been weakened by the French president, Nicolas Sarkozy, who successfully poached a number of its high-profile members and supporters for his government of ?unity? last year.