France’s presidential race headed into its home straight yesterday as ex-International Monetary Fund boss Dominique Strauss-Kahn, a Socialist once tipped to win the vote, blamed Nicolas Sarkozy for his spectacular downfall.

The claim came as the battle between Sarkozy and the front-running Francois Hollande grew ever more bitter, with the incumbent accusing the Socialist of subjecting him to a “Stalinist trial” over his bid to woo the far right.

Strauss-Kahn, in his first major newspaper interview since his disgrace a year ago, told The Guardian that his fall was orchestrated by opponents to prevent him from standing as the Socialist candidate in the election.

The ex-IMF boss had been favoured to win the vote until May last year, when he was arrested in New York and accused of sexually assaulting a hotel maid, Nafissatou Diallo. The charges were later dropped.

Strauss-Kahn said that although he did not believe the incident with Diallo was a setup, the subsequent escalation of the event into a criminal investigation was “shaped by those with a political agenda”.

“Perhaps I was politically naive, but I simply did not believe that they would go that far – I didn’t think they could find anything that could stop me,” Strauss-Kahn told the British daily.

The Guardian said it is clear that the “they” refers to people working for Sarkozy and his UMP party.