More than 20,000 Muscovites took to the streets on July 20 for a sanctioned protest against the disqualifications, while opposition leader Aleksei Navalny has called for an even larger, unsanctioned rally in the center of the city on July 27.

The would-be candidates were barred from the race after government graphologists rejected many of the voter signatures they submitted -- grounds that protesters say were trumped up to keep genuine independents off the ballots and ensure the ruling United Russia party and others who do President Vladimir Putin’s bidding maintain dominance.

"If the United Russia swindlers don't register the independent candidates and spit on the opinions of the citizenry, then all of us…will come to the mayor's office at Tverskaya 13," Navalny wrote in a social media post on July 20.

Rejected candidate Lyubov Sobol, a lawyer with Navalny's Anti-Corruption Foundation, also called for mass protests after a meeting between the disqualified candidates and Central Election Commission (CEC) Chairwoman Ella Pamfilova.

"We have no other choice," Sobol said. "We must take to the streets and I call on everyone to come to the Moscow mayor's office at 2 p.m. on Saturday [July 27]." Kremlin-backed Moscow Mayor Sergei Sobyanin’s office is a short distance up Tverskaya, a main thoroughfare, from Red Square and the Kremlin.

The July 20 demonstration was the largest in Russia to demand free elections since the massive 2011-12 protests against Putin's return to the Kremlin for a third term as president following the single term of placeholder Dmitry Medvedev.

Putin, who has been president or prime minister since August 1999, was elected to a fourth term in 2018.

Carrot And Stick

The Russian authorities appear to be adopting a carrot-and-stick approach as the July 27 demonstration nears. On one hand, Pamfilova met with the opposition candidates and heard their complaints -- one of which was that Moscow election officials had refused to meet with them and hear their complaints.

Pamfilova "generally tries to be a pleasant woman in all situations, including in conversations with the opposition," Sergei Mitrokhin, a leader of the liberal Yabloko party and a disqualified candidate who attended the meeting, told RFE/RL. "She is personally charming and she makes use of this [quality] actively all the time.

Pamfilova promised to consider the complaints of the disqualified candidates, but warned them that the CEC does not have the authority to overturn decisions of the Moscow Election Commission. She said the law grants local election commissions such autonomy to prevent Moscow from exerting influence on them.

Pamfilova also urged candidates not to participate in protests, saying "the influence of street protests on the CEC is zero."

Navalny took these words as a challenge.

"To summarize the meeting in plain language," heposted on Twitter , "Ella Pamfilova is playing for time and the decision on whether to register the candidates will be made based on the size of the [July 27] demonstration at the mayor's office."

Stern Warning

Just hours after the Pamfilova meeting, however, Moscow police picked up Navalny outside his home as he went for a run.

Hours later, a spokeswoman for Navalny said the opposition leader had been sentenced to 30 days in jail on charges of calling an unauthorized protest.

The same day, the Investigative Committee announced the opening of a criminal case, charging that "members of one movement" had attempted to pressure Moscow election officials in their lawful duties by holding demonstrations outside their offices.

Both moves seem bent on sending a stern warning as the proposed July 27 demonstration approaches.

The Moscow-election protests may have been strengthened by the case of investigative journalist Ivan Golunov earlier this summer.

Moscow police arrested Golunov in June on drug charges, but released him days later in the face of public outrage over what colleagues and protesters said were transparently flimsy and fabricated allegations. Several high-ranking Moscow police officials were later sacked over the incident, and a number of investigations were launched.

The independent candidates -- including Sobol, Mitrokhin, former Russian State Duma Deputy Dmitry Gudkov, opposition activist Ilya Yashin, and Navalny associate Konstantin Yankauskas -- have complained of harassment, threats, and violence throughout the process of gathering the signatures.

Their signature collectors were harassed by police and targeted by thugs who threw feces at them and tore up their signature lists.

The unfair treatment continued as the Moscow Election Commission examined their signatures, the would-be candidates told RFE/RL.

"The signatures of the 'independent' candidate from United Russia and those of a candidate from the Communists of Russia Party were only checked for half an hour," Yankauskas said. "The graphologist just scanned the signatures randomly. But my signatures were studied for a total of 10 hours over two days. This was a violation of the principle of equality among candidates."

Yankauskas added that election workers spent 40 minutes with pens in hand leafing through his signatures before they handed them over to the government's graphologists.

He also said that nearly 600 of his signatures were disqualified because election officials determined that the receipt he had obtained to show that he had paid for the official forms was a forgery. Yankauskas claims the form he submitted was switched for the fake.

"On this basis, all the signatures we collected between July 7 and July 14 were disqualified," he said.

Mitrokhin said that a worker at the state-controlled Sberbank put the wrong date on the receipt for his signature forms, resulting in the disqualification of many of his signatures as well, despite a CEC guideline that mistakes committed by officials should not be held against candidates.

Sixteen regions will choose governors in Russia's September 8 elections, including the city of St. Petersburg. Fourteen regions and the city of Moscow will select legislative assemblies, and 21 other cities will choose municipal councils.

United Russia has entered the election season with a record-low public approval rating. Analysts and Kremlin critics say the authorities are resorting to numerous "dirty tricks" and other tactics to ensure the party maintains the grip on power it has enjoyed through most of Putin's nearly two decades at the country's helm.

With reporting by RFE/RL Russian Service correspondents Mikhail Sokolov and Mark Krutov