A Russian parliamentary ethics committee on Wednesday censured a high-profile young opposition lawmaker and urged him to quit after he delivered a speech in the United States criticising President Vladimir Putin.
"The State Duma ethics committee has stripped Dmitry Gudkov, a lawmaker with A Just Russia faction, of the right to speak publicly at plenary sessions for one month and also proposed that he make a public apology and hand in his mandate," the ruling United Russia party said.
"This decision has been taken following an inquiry by all four parliament factions into Gudkov's trip to the United States," the party, which controls the Russian parliament, said in a statement.
In early March, Gudkov, 33, travelled to Washington where he gave a speech at a forum organised by Freedom House, a pro-democracy group funded by the US government and private groups.
In the speech, delivered in English, he lambasted "repressive methods of Putin and his minions", and called on Washington to help expose corrupt officials in Russia by providing information on their accounts in Western banks.
Gudkov, who regularly speaks at opposition rallies, is refusing to quit.
Writing on his blog, he said it was not the first prompting by pro-Kremlin lawmakers for him to hand in his mandate.
"As always, I will answer them: only after you, gentlemen!" he said.
"Alas, the ethics commission has turned into a body fighting the opposition.
"Your censure is not worth anything, either," he added.
"If you are against creating an international mechanism to fight corruption and money-laundering, then you will have to explain that to your voters during the next elections, and I think it is unlikely that they will understand you."
The entire State Duma, Russia's lower house of parliament, is expected to address Gudkov's behaviour later this week at a plenary session, a Duma spokeswoman said.
Dmitry Gudkov's father, Gennady Gudkov -- who is also a vocal member of the anti-Kremlin opposition -- was expelled from the parliament in September over allegedly conflicting business interests.
Both men were expelled from their left-leaning party, A Just Russia, earlier this week because of their opposition activities.
The anti-Putin opposition movement argues the whole of the parliament lacks legitimacy because 2011 parliamentary elections were slanted in favour of the ruling party.
The State Duma has been hit by a rash of scandals in recent weeks, including corruption allegations.