"We need to show the authorities that we don't agree to be ruled by swindlers and thieves," said Andrei Semyonov as he stood outside a downtown Moscow metro station to advertise Saturday's "For Fair Elections" protest near Red Square, RIA-Novosti reported.

"The cold shouldn't matter at all in matters like this," he said, wrapped up well against temperatures of around minus 20 degrees Celsius (minus 4 degrees Fahrenheit).

Six thousand people had earlier pledged on social networks to hand out rally flyers and leaflets and organizers said, as quoted by the Gazeta.ru online paper, that activists were outside "all Moscow's metro stations" on Thursday evening.

Almost five times more have so far indicated they will attend the protest, the third since December 4 parliamentary polls saw widespread allegations of vote fraud in favor of Prime Minister Vladimir Putin's United Russia party.

The previous protests drew an estimated combined total of 100,000 and were the largest show of anti-Kremlin dissent for almost two decades.

"Of course, what with the weather being like it is, I guess fewer people will turn up on Saturday," said activist Artyom Potikhalichev as he handed on rally flyers on Moscow's main tourist stretch, the Old Arbat.

Putin accused the U.S. in December of backing the vote fraud protests and said Secretary of State Hillary Clinton had "given a signal" to opposition leaders. He also said that many of the protesters were being paid to attend rallies.

"Of course, Hillary paid me herself!" Artyom joked. Turning serious, he said he was braving the cold because he was tired of the authorities' "lies and corruption".

The February 4 rally comes exactly a month before Putin is due seek a third stint in the Kremlin after being barred by the Constitution from standing for a new, consecutive term. While polls suggest he remains Russia's most popular politician, analysts have said that rising discontent among educated urbanites could see him forced into a potentially damaging runoff.

One of the protest organizers, former deputy prime minister Boris Nemtsov, also promoted the upcoming rally, handing out flyers at the Tretyakovskaya metro station, across the Moskva river from the Kremlin, the opposition Novaya Gazeta newspaper reported.
The paper's online version also said that he was taunted by pro-Kremlin activists, who accused him of corruption during his time in office.

Around 300 people had also vowed to promote on Thursday evening a February 4 counter rally in support of Putin and United Russia. Media reports said activists clad in "USSR 2.0" tops could be seen at five Moscow metro stations. The Russian capital has over 180 metro stations.

"Our rally is for Russia, to make it strong and independent, and to prevent it becoming a toy for foreign hands," organizers of the pro-Putin rally said earlier in a statement.

Some 15,000 people are expected to attend the pro-government demonstration. Free taxis will be on hand to ferry participants to the rally, organizers said on Thursday. United Russia say they are not behind the event, but that senior officials may attend.

Members of the tiny, unregistered political party Volya also handed out flyers in Moscow on Thursday, but in their case calling for people not to attend the February 4 rallies, which they predicted could see "instigated disorder" and the subsequent military intervention in Russia by NATO troops.

Volya activists standing outside the Arbatskoye metro station refused to identify themselves to RIA Novosti.

Russia's chief doctor, Gennady Onishchenko has also called on Russians to give the rallies a miss, saying they risk catching flu or other illnesses in the cold. He made similar appeals ahead of the December rallies.

The head of the country's powerful Orthodox Church, Patriarch Kirill has urged people to stay at home and pray for "holy Russia."