It’s only been a little over two years since the Socialist Party’s Francois Hollande was elected President of France with the highest of hopes. The centre-Left had had a rough few years in Europe; this was the big sign that it was on the way back. Hollande’s message of responsibility, moderation and winding back austerity won widespread support.

But times change. Hollande’s government has failed to revitalise the French economy, and the President has also faced unwelcome publicity for his private life. Big losses in local elections earlier this year forced the resignation of his prime minister, and in recent European parliamentary elections the Socialists could only mange third place, with 14%, well behind both the centre-Right Union for a Popular Movement (UMP) and the far-Right National Front.

Hollande is not up for re-election until 2017, but his party is already making noises about seeking another standard-bearer. One opinion poll a few weeks ago found only 3% of voters wanted Hollande to be the Socialist nominee.

There’s now a real fear that the Socialists could again, as in 2002, be relegated to third place in the presidential election, leaving the UMP and the National Front’s Marine Le Pen to fight it out in the runoff.

So it was a rare piece of good news for the Socialists last week when Hollande’s colorful UMP predecessor, Nicolas Sarkozy, was taken into custody for questioning over allegations of corruption. It’s alleged that he tried to trade favours with a judge in order to obtain information about a different investigation, into illegal campaign donations from Libya’s Colonel Muammar Gaddafi.

Sarkozy narrowly lost the 2012 election to Hollande and has had his eye upon a comeback. It’s impossible to say where the current investigation may go — Sarkozy denies any wrongdoing and accuses the magistracy of being politically motivated — but it may well derail his campaign in the same sort of way that Dominique Strauss-Kahn, once front-runner for the Socialist nomination last time around, was put out of contention by rape charges in New York (of which he was later cleared).

The difference is that while Strauss-Kahn was a runaway favorite among the Socialists until he ran into legal trouble, Sarkozy has always been regarded as a bit of a cuckoo in the UMP nest. Like Margaret Thatcher or Kevin Rudd, his colleagues tolerated him only as long as he looked a winner. Unless he can demonstrate revived electoral appeal, they will probably prefer a more conventional choice.

In Sarkozy’s absence, the centre-Right has spent the last couple of years fighting among itself. Jean-Francois Cope (formerly party secretary) defeated Francois Fillon (Sarkozy’s former prime minister) by a wafer-thin margin for the party presidency in 2012, but he in turn resigned this year following the European parliamentary election. Cope, Fillon and another former prime minister, Alain Juppe, have all expressed their interest in the presidential nomination, although Cope has said he would be willing to stand aside for Sarkozy.

The subtext of much of the internal division is how the UMP should place itself ideologically: should it shift to the hard right to try to steal votes back from the National Front, or should it court the middle ground and pursue alliance with the centrist forces? Cope and Sarkozy are identified with the first option; Fillon and Juppe with the second.

So far, the UMP’s infighting doesn’t seem to have done much to help the Socialists in the polls. But if Sarkozy continues to fight for his political rehabilitation and the resurgence of the National Front continues to spook his centre-Right colleagues, then Hollande may hope to eventually reap the benefit.

At this stage, it seems to be about the only hope he’s got.