PARIS - Dominique Strauss-Kahn, the former IMF chief who is back home in France with his career in tatters after a sex-assault scandal, is likely to take a role in the left's 2012 election campaign, a political ally said on Monday.

Pierre Moscovici, a Socialist Party lawmaker and former government minister, was one of Strauss-Kahn's biggest backers for the 2012 election and is now coordinator for the campaign of the Socialist Party's new favourite, Francois Hollande.

"I think he'll do it," Moscovici said, asked on BFM TV whether the former left-wing favourite to unseat President Nicolas Sarkozy next year would now put his energies into helping a rival get elected.

"This is a man who has devoted his life to the public domain, whose passion is politics, who is committed to the left," Moscovici said. "How could he stay out of the supreme confrontation when we have Nicolas Sarkozy in front of us and a categorical imperative to beat him?"

Socialist Party spokesman Benoit Hamon was more cautious, telling a news conference Strauss-Kahn's voice could be useful in the left's campaign but was not essential.

Hollande's rival Martine Aubry is a few points behind in polls, both with enough support to defeat centre-right Sarkozy.

Strauss-Kahn's public relations adviser Anne Hommel told reporters massed outside his Paris apartment that he would speak in public in the two weeks for the first time since his May arrest in New York on charges, later dropped, of attempted rape.

Reflecting the party's unease with being too closely linked with Strauss-Kahn in the wake of the scandal, Hamon said the Socialists had not factored in a role for him. "We are focused on political actions for the short and medium term," he said.

FRENCH COMPLAINT STILL LURKS

Strauss-Kahn arrived back in France on Sunday with his wife Anne Sinclair. He smiled but stayed silent as he fought his way through a sea of flashing cameras at Roissy Charles de Gaulle airport and at his central Paris apartment .

With his allies now all backing other candidates for the upcoming Socialist primary and his image badly stained by his nine-minute sexual encounter with the maid, which his lawyers say was consensual, Strauss-Kahn's political future is unclear.

The most likely platform for him to speak publicly would be a TV talk show from where he could discuss the global economy.

He may decide to wait until after the Paris prosecutor's office announces its decision on whether a separate sex assault complaint against him by a French writer 30 years his junior warrants opening a formal inquiry. That decision is expected in the days or weeks ahead.

Le Figaro newspaper quoted an unnamed person close to Strauss-Kahn as saying he would give his account of the events in New York ahead of a likely televised debate between Socialist primary contenders in mid-September.

"He has to speak soon, but not say too much," the person was quoted as saying. "All this needs to be purged by September 15."

The Socialists will vote in October to pick their candidate for the two-round presidential election next April and May.