By Richard Galpin
BBC News, Moscow
Election commission head Alexander Veshnyakov has been removed as Russia gears up for parliamentary and presidential polls in the next year.
Mr Veshnyakov had been in post for eight years
Mr Veshnyakov had spoken out against the dominance of the pro-Kremlin party, United Russia, which controls the national parliament.
Last weekend, it swept the board in a series of regional elections.
There has been no official explanation for Mr Veshnyakov's removal. He had run the commission for eight years.
He had overseen both presidential elections won by Vladimir Putin.
Six of the 15 members of the election commission have been changed in a reshuffle. Mr Veshnyakov, the chairman, has been removed.
Most of the new members were hand-picked by President Putin.
Recently Mr Veshnyakov had begun to speak out about the lack of choice for voters, with the United Russia party - which supports Mr Putin - consolidating its grip across the country.
Political analysts also say he had annoyed the Kremlin by criticising changes to the electoral laws which make it more difficult for smaller parties to enter parliament.