IMF chief Dominique Strauss-Kahn, right, shown in February, has been cited in polls for months as the strongest potential challenger to President Nicolas Sarkozy, left, in France’s coming presidential elections. (PHILIPPE WOJAZER/REUTERS)

Whatever its outcome in the courts, IMF chief Dominique Strauss-Kahn’s arrest seemed likely to change the political landscape in France.

The longtime Socialist Party figure and former finance minister has been cited in opinion polls for months as the strongest potential challenger to President Nicolas Sarkozy in presidential elections scheduled a year from now. But that equation was suddenly disrupted, commentators said, with the news from New York that he arrested in connection with an alleged sexual assault on a hotel housekeeper .

“The most likely outcome is that the case will stick, and even if he pleads not guilty — which he may be — he won’t be able to be a candidate for the Socialist Party presidential primary,” Jacques Attali, a fellow Socialist leader, told French reporters. “And he won’t be able to stay on at the International Monetary Fund.”

Bernard Debre, a member of parliament from Sarkozy’s conservative coalition, was more personal — and more damning. In a conversation with Europe 1 radio, he called the arrest “very humiliating for our country” because of Strauss-Kahn’s prominence in Washington and his role as a representative of France.

“It is a disaster for our country and for France’s image,” agreed Renaud Muselie, another member of parliament from Sarkozy’s Union for a Popular Movement, “because he is head of the IMF, and it completely reshuffles the cards for the presidential election.”

Marine Le Pen, who recently took over from her father as head of the far-right National Front, reminded reporters that Strauss-Kahn has long suffered from a reputation as a crude womanizer and said therefore that she was not surprised about the latest episode. She predicted that, now that the New York affair had exploded in public, more revelations would soon emerge.

Strauss-Kahn, who took over the IMF in 2007 on a nomination by Sarkozy, was involved the following year in a scandal concerning his relationship with a woman of Hungarian origin who headed the fund’s Africa department. The bank’s board, after considering whether Strauss-Kahn was guilty of abuse of authority, reprimanded him for what it called a serious error of judgment but kept him in his job.

His wife, the former television interviewer Anne Sinclair, publicly forgave him for what she described in her blog as a one-night stand.

The sexual assault charges came just as another media furor was dying down, this one over photos of Strauss-Kahn and Sinclair getting out of a $150,000 Porsche Panamera on a Paris street. Although it later became known that the car belonged to a friend, the photo raised questions about the couple’s lifestyle — with two toney apartments in Paris, a vacation home in Marrakesh and a residence in Washington — with and whether it was compatible with someone claiming to represent the Socialist Party.

Citing a duty to remain silent because of his job in Washington, Strauss-Kahn had not openly declared his candidacy for the party’s presidential primary despite the polls citing him as the best candidate against Sarkozy. But he was widely expected to step down at the IMF and declare for the presidency sometime this summer, after negotiations for another Greece economic rescue package at the Ggroup of Eight summit scheduled next month in Deauville.