Ségolène Royal suffered a fresh setback to her presidential aspirations yesterday when a disgruntled adviser attacked her as an incompetent amateur and egomaniac who was a danger to France.

Eric Besson, 46, an MP who resigned last month as the Socialists’ chief economic strategist, says in a book: “In all conscience I do not think that Ségolãne Royal should become president of the Republic. I do not wish it for my country. I fear it for my children.”

He adds: “She has an ultra-personal conception of power. Her only motive is personal glory. She uses and abuses demagoguery. We are in France, not in Latin America, even if the resemblances are disturbing.”

Ms Royal dismissed Mr Besson’s hastily written book, Who Knows Madame Royal? as insignificant, and her aides depicted it as the revenge of a bitter loser. However, its portrait of Ms Royal as a scheming lightweight has hit hard because Mr Besson voices publicly what many of her senior colleagues say in private.

This week the party’s elders feuded in public over how to save her candidacy from defeat in the April 22 first round by François Bayrou, the centrist candidate who is winning support from disappointed royalistes. Other senior Socialists openly joke about the amateurism of her campaign.

Mr Besson, a former businessman whose job was to flesh out the policies sketched by Ms Royal, resigned in protest over being ignored by the candidate and her team. He lso resigned his seat and left the party.

The title of his book comes from the humiliating putdown that Ms Royal inflicted on him after his resignation. “Who here knows Eric Besson?” Ms Royal asked a crowd of factory workers.

In the book Mr Besson says that Ms Royal and the “squires” in her “ ancien régime court” invent big economic policy on the hoof and in ignorance. With one stroke of a pen, she wiped out France’s nuclear electricity programme, then revived it later, he said. Her claim to have devised her manifesto after months of consultation with ordinary citizens was a lie, he said. “Everyone knows that it is false . . . Pure demagoguery. She represents the burial of our entire culture of government.” Ms Royal was an archaic, unreformed leftist, despite her claims to modernity, said Mr Besson. “She has a deaf hatred for modernity, science, reason and progress.

“If she wins, I pity her prime minister. He will have to execute vague policy under the command of a president who promotes a personality cult. We are on a very dangerous slope for France if she wins,” he added.

“If she loses, the Socialist Party will have abandoned its principles and its identity for an illusion . . .”

Despite the bloodletting among Socialists Ms Royal’s campaign has not completely run out of steam.

Polls this week have shown her ahead of Mr Bayrou, the leader of the small Union for French Democracy. She is still three or four percentage points behind Nicolas Sarkozy, the conservative candidate, who is expected to face a run-off vote on May 6 against either Ms Royal or Mr Bayrou.

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