Russia's Constitutional Court has approved constitutional amendments that could enable President Vladimir Putin to stay in power for another 16 years.

The court's March 16 announcement comes three days after all Russian regions approved the controversial bill on amendments to the constitution.

The legislation sets Putin's previous presidential term count back to zero because of the sweeping changes to the constitution, which sparked protests in Russian cities.

Putin's current term, his second consecutive six-year term, is slated to end in 2024. The existing constitution prohibits presidents from serving more than two consecutive terms, but the amendments would enable him to seek a fifth overall presidential term in 2024, and conceivably a sixth in 2030.

Final approval will come if more than half of the country's voters support it in a nationwide vote scheduled for April 22.

Putin, a 67-year old former KGB officer, has ruled Russia as a president or prime minister for more than 20 years.

The idea about setting Putin's previous presidential terms to zero was unexpectedly voiced at a session of the parliament's lower chamber, the State Duma, on March 10.

Valentina Tereshkova, an 83-year-old lawmaker and the world's first woman to fly to outer space, put forward the proposal, which other lawmakers quickly approved.

Critics say Tereshkova was likely used by the Kremlin as a tool in a Soviet-style "initiation" of a political move. In some cities people have launched campaigns to rename local streets named after the world's first female cosmonaut, saying that her role in Putin's move to keep his grip on power "set her glorious past to zero."

In the capital of the Russian region of Mordovia, Saransk, a campaign has been launched to rename Tereshkova Street after Laika -- a Soviet space dog who became one of the first animals in space and the first animal to orbit the Earth in 1957.

A similar petition launched online by activists in the largest Siberian city, Novosibirsk, aims to change Tereshkova Street in that city to be named after the second female cosmonaut and the world's first woman to perform a spacewalk, Svetlana Savitskaya, and has been signed by more than 4,000 local residents.

Activists in Moscow, meanwhile, have asked the city administration to allow them to hold demonstrations against the amendments on March 21-22.

On March 16, Moscow Mayor Sergei Sobyanin signed a decree banning all mass gatherings and public events in the Russian capital until April 10, due to the coronavirus pandemic.

With reporting by RFE/RL's Tatar-Bashkir Service, TASS, and Interfax