The shaky campaign of Ségolène Royal for the French presidency suffered a fresh blow yesterday when her main economic adviser resigned amid growing Socialist dismay over her failure to revive her run for the Elysée Palace.

Ms Royal’s team was locked into a “spiral of depression” after the latest embarrassment in her once-flawless campaign, said the newspaper Le Monde. Ms Royal, 53, was booed by schoolchildren on a visit to a sports ground on Tuesday and is being deserted by stars of the intellectual world, a traditional bastion of the Left.

She also failed to achieve a bounce in the polls from her manifesto launch on Sunday, leaving Nicolas Sarkozy, 52, the candidate for the centre-right Union for a Popular Movement (UMP), with a clear lead.

The Socialists sought to play down the departure of Eric Besson, the party’s chief of economic policy. The MP walked out on Tuesday in a feud with François Hollande, the party chief and Ms Royal’s domestic partner, over the manifesto.

Ms Royal ordered her team to focus on promoting the generous financial measures that she promised without being pinned down on their funding. But Mr Besson, Mr Hollande and others came under media pressure to produce figures after Ms Royal failed to mention costs while preaching the urgency of curbing the national debt. They produced the figure of 35 billion extra euros per annum and Mr Besson amplified the detail.

On Wednesday, Mr Hollande rounded on Mr Besson for this and he resigned on the spot, complaining about disorganisation and incoherence in the campaign, party sources said.

The incident has reinforced the image of disarray in a campaign in which Ms Royal and her close staff have kept a distance from the Socialist machine and failed to recruit her former party rivals in her cause. Tension between Mr Hollande and his partner is also troubling the campaign, according to insiders.

The departure of Mr Besson was a sign “at best of tensions in Royal’s team, at worst of persistent malfunctions in the coordination of her campaign”, said the newspaper Libération, which supports Ms Royal.

In another fumble this week, the campaign retracted an article under Ms Royal’s name that it had supplied to the magazine Témoignage Chrétien. The piece, which was scathing about President Chirac’s highly personal conduct of relations with Africa, had not been authorised, said her campaign.

The errors made by the Royal staff have been seized upon by the Sarkozy team, a well-oiled machine in comparison. Visiting the French Indian Ocean island of La Réunion yesterday, Mr Sarkozy quipped: “She shouldn’t change a single thing. If you cannot rally your own family, you can hardly rally all the French.” The office of Mr Sarkozy in Paris said that the Socialist squabble over economic plans was proof that they lacked credibility.

The sense of momentum created by the Sarkozy campaign was reinforced by polls which show that, despite media praise for her performance on Sunday, Ms Royal has not achieved an increase in support.

Jean-Daniel Lévy, of the CSA institute, said that the French had viewed Ms Royal’s manifesto speech as a catalogue of left-wing promises rather than a vision. Voters have a stronger understanding of Mr Sarkozy’s entrepreneur-ial vision of a France in which “you work more to earn more”.

The Socialists are worried by polling figures that show overall support for left-wing candidates in the first round is at its lowest for years, despite the unpopularity of the centre-right Chirac administration.

Jean-Louis Bianco, joint campaign director for Ms Royal, admitted that “the Left is extremely weak in the first round . . . There has to be a [new] campaign dynamic.” The next chance for Ms Royal to win support comes on Monday, when she is questioned by 100 members of the public in a two-hour television session.

There was more bad news for Ms Royal yesterday when Renaud Séchan, one of the country’s best-loved pop singers and a veteran of left-wing causes, announced that he did not think much of the Socialist candidate and was moving to London.

Renaud, 55, said that he had always voted for the Left and would do so for the rest of his life “even if the candidate on the Left does not stand for the Left that I love and . . . is not what I expect of the real Left”. He said: “Like a lot of voters, I am lost what to do in this election, especially the first round.”

Read Charles Bremner's blog on Paris photography

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