Ilya Ponomaryov, a regular at opposition meetings who has lived in the United States since 2014, has been accused of complicity in the embezzlement of USD 750,000 from the Skolkovo Foundation, a high-tech project the Kremlin had hoped would be its answer to Silicon Valley.
The opposition has dismissed the charges as politically motivated.
Today, 413 lawmkers voted in favor of stripping Ponomaryov of his seat in the legislature. Only three State Duma deputies voted against the proposal, opposition lawmaker Dmitry Gudkov wrote on his Facebook page.
A Russian court last year had ordered Ponomaryov's arrest in absentia over the alleged embezzlement after he was stripped of his parliamentary immunity from prosecution.
Ponomaryov, one of the few public figures openly critical of President Vladimir Putin, has denied any wrongdoing.
In 2012, along with two other opposition lawmakers, Ponomaryov staged a filibuster, speaking for 11 hours straight when the legislative body debated increasing fines for the participants of unsanctioned protests.