The Russian government is to resign, hours after President Vladimir Putin announced plans in parliament to change the constitution.
Mr Putin has proposed a nationwide vote on changes that would shift power from the presidency to parliament.
He has asked Prime Minister Dmitry Medvedev to take up the post of deputy head of the National Security Council.
Mr Medvedev said the president’s proposals would significantly change Russia’s balance of power.
“These changes, when they are adopted… will introduce substantial changes not only to an entire range of articles of the constitution, but also to the entire balance of power, the power of the executive, the power of the legislature, the power of judiciary,” Mr Medvedev said.
“In this context… the government in its current form has resigned.”
The announcement came as a surprise, and in a statement Mr Putin thanked the government for what it had achieved.
BBC Moscow correspondent Sarah Rainsford said the reason why Mr Putin had removed Mr Medvedev was unclear.
President Putin’s fourth term in office is due to end in 2024, and under the existing constitution he would not be entitled to another term.