Vladimir Putin launched an extraordinary attack on the United States yesterday, blaming the Americans for stoking discontent in Russia in his first major comments on the street protests that have sprung up since parliamentary elections on Sunday.
As Russians continued to sign up in thousands on Facebook for a co-ordinated series of protests planned tomorrow, the Russian Prime Minister said that the US had spent "hundreds of millions of dollars" trying to influence the outcome of the elections.
He personally accused Secretary of State Hillary Clinton of igniting the protests, claiming that she "gave a signal" to Russia's opposition leaders by describing the election as rigged. "They heard this signal and with the support of the US State Department began their active work," said Mr Putin.
Ms Clinton, who had said Russian voters deserved an investigation into allegations of fraud in Sunday's elections which gave Mr Putin's United Russia party 49 per cent of the vote, said later yesterday that her criticism had been "well-founded". International observers have said the poll was rigged in Mr Putin's party's favour.
The spat over the elections, as well as disagreements over missile defence, threaten to derail entirely the "reset" in relations between the two countries. US Senator John McCain has also irritated the Russians, tweeting a link to an article about Russia to his 1.7m followers, and adding the message, "Dear Vlad, the Arab Spring is coming to a neighbourhood near you".
Mr Putin, who plans to return as president next year, has frequently claimed that his political opponents are traitors, financed from abroad. He has described them as "jackals" waiting outside foreign embassies for handouts, and just before last weekend's elections he said that foreign governments wanting to influence Russian politics would be unsuccessful because "Judas is not the most popular figure among our people".
But with protests now attracting thousands of young Russians who have never demonstrated before, it is not clear whether playing the "foreign enemy" card will work for Mr Putin.
Protests are planned in 78 Russian towns and cities for tomorrow, by far the biggest of which in Moscow. About 50,000 police and 2,000 paramilitary troops are patrolling the city's streets, backed by water cannons.
The Mayor's office asked the organisers to move the meeting from Revolution Square, near the Kremlin, to a different location, but it was unclear if they would agree. Authorities say a maximum of 300 people can protest if the rally is on Revolution Square, and if more attend, they will be arrested.
By yesterday, 30,000 had signalled their intention to attend on a Facebook group and 15,000 more signed up to a similar group on the Russian social network Vkontakte.
Mr Putin said that if people wanted to "act within the law" then they should be allowed to express their opinions, but said most Russians were not in favour of protests.
"We know that in our country, people do not want events to go the same way as they did in Kyrgyzstan, or in the recent past in Ukraine," he said. "Nobody wants chaos."
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