In 1904 he became a member of the Bolshevik Moscow Committee where he soon took on a leading role, editing the newspaper "Rabochii". He was arrested for his part in the Moscow armed Uprising of 1905, which led to his exile in Yeniseysky District. However he soon escaped to Omsk and then to Saint Petersburg. He attended the Fifth Congress of the RSDLP in London, 1907. Here he was elected to the Bolshevik Centre, the clandestine leadership of the Bolshevik faction. He was arrested again later that year and exiled to Siberia, and then to Turukhansky District. He escaped again and by 1909 was in Paris.