The lawmaker, Vladimir A. Pekhtin, said that he did not want the scandal to taint his party colleagues in United Russia, and announced his departure at a morning parliamentary session.
He said he had not broken any law, but that “there are very controversial documents that have been made public on the Internet,” and it was necessary to clear up “obvious legal misunderstandings.”
“I will give up my mandate, which I always achieved in honest political battle, and my opponents, my rivals, know this,” he said, in comments broadcast on television. “Nevertheless, I will not cling to it. Because I think that my personal matters are secondary to United Russia. Thank you for many years of work, and for your trust.”
Whether he surrendered his seat voluntarily or under pressure from the Kremlin, Mr. Pekhtin’s departure set a precedent in the Russian government, where high-level corruption and lavish spending overseas have developed into a serious political liability. It represents a victory for opposition activists, who have never achieved such a swift response to an exposĂ©.
Officials, meanwhile, have been given a powerful reminder of their own vulnerability, said Mikhail Y. Vinogradov, chairman of the St. Petersburg Politics Fund. He added that it is not yet clear whether this case represents a one-time occurrence or “a change in the rules of the game.”
“This is a way to show that discussion of a ‘battle against corruption’ leaves the majority of officials without protection,” he said. “Naturally, officials’ anxiety over their property will grow for the time being. There won’t be any attempts to torpedo this campaign — they will simply hope that this is just another campaign that will exhaust itself in three or four months. That’s what the representatives of the elite will count on.”
The blogger Aleksei Navalny, who published documents about Mr. Pekhtin’s extensive real estate holdings last week, was jubilant, remarking that “now he can finally move to Miami and live in peace, without having to listen to any complaints.”
“In fairness, one must acknowledge that Mr. Pekhtin’s actions show that somewhere deep inside him there are remnants of a conscience,” he wrote on the Web site of Ekho Moskvy, a radio station. “Maybe other members of United Russia felt this, and that’s the reason they named him to the ethics committee? Let’s watch how the others who are hiding foreign property behave.”
Mr. Navalny published the property records last Wednesday, a day after Mr. Putin proposed legislation that would bar senior Russian officials from holding bank accounts or owning stock outside the country.
The proposal did not prohibit officials from owning real estate overseas, but signaled a Kremlin crackdown on their lavish spending abroad, so the revelations about Mr. Pekhtin came as an ill-timed embarassment.
The records showed the lawmaker’s name on the deeds of at least three properties in Florida, including a South Beach apartment bought last year for nearly $1.3 million, in a building where Mark Cuban, the owner of the Dallas Mavericks basketball team, also owns a unit.
Late last year, the newspaper Vedomosti published a report on a huge mansion outside St. Petersburg and other properties which Mr. Pekhtin had not disclosed.
Mr. Pekhtin initially shrugged off the reports, telling the newspaper Izvestiya that he had “practically no” real estate holdings outside Russia, though his grown son did. Within a matter of hours, however, he announced that he was temporarily relinquishing his position as chairman of the parliamentary ethics committee until his name was cleared by an investigation.
On Wednesday morning, Mr. Pekhtin cast the scandal as a salvo in a larger standoff between social forces in Russia.
“In this case, our opponents are not interested in Pekhtin,” he said, according to Interfax. “They need to discredit the Parliament, the authorities, which are represented by every person sitting in this hall, and every one of us may turn out to be a target for them. As an honest person, I do not want and cannot make peace with this, and I do not want the shadow of unfounded allegations to fall on our party.”
After Mr. Pekhtin made his announcement, fellow lawmakers gave him a standing ovation and warmly applauded. Many went out of their way to praise his decision. But Sergei Mironov, head of the minority A Just Russia party, said he expected Mr. Pekhtin’s decision marked the beginning of a process, not the end.
“Pandora’s box has been opened,” said Mr. Mironov, in comments broadcast on Channel One. “I don’t doubt that the sixth sitting of the State Duma will have a record number of early terminations of deputies’ authority. For me it is completely obvious that, if there were not some real facts there, the deputy would not have voluntarily given up his authority.”