Russia's regional elections pose serious test for pro-Kremlin party - CNN

He fell ill on a tour to Siberia where he met local candidates taking part in his project called "Smart Voting" and filmed investigation reports on the activities of local United Russia members.

The "Smart Voting" strategy promoted by Navalny urges Russians to vote tactically in support of a single candidate on any ballot most capable of unseating an incumbent from United Russia.

Navalny unveiled "Smart Voting" during local elections in Moscow and St.

Petersburg in 2018, costing United Russia dozens of seats in regional bodies.

This year, Navalny headquarters runs the platform under the "Nullify United Russia" slogan in an apparent reference to a recent constitutional amendment resetting the clock on Vladimir Putin's presidential term count.

United Russia's popularity declined in the past years as its image has been marred by unpopular reforms and corruption scandals, many of them exposed by Navalny's Anti-Corruption Foundation, with Navalny himself giving the party a moniker "the party of crooks and thieves."

This is the first election Russia has held since the vote on controversial constitutional amendments that gave Putin grounds to stay in power until 2036.

The vote spans three days between September 11-13 in an attempt to limit crowds and prevent the spread of coronavirus, a practice adopted in the July vote on constitutional amendments, which independent monitoring organizations say lowers voting transparency and makes it easier to falsify votes.

"Early voting traditionally makes the election process much less transparent," monitoring organization Golos said in a statement.