Vladimir Putin said on Tuesday that mass protests against his 12-year rule were being stoked by a hollow collection of leaderless opposition groups who wanted to sow chaos in Russia.
In his first comments since Saturday's protest, Russia's prime minister said it was impossible to annul the December 4 parliamentary election - the opposition's key demand - but promised the March presidential vote, in which he is running, would be transparent.
Comparing protesters to Russian revolutionary Leon Trotsky, Putin said they were more interested in sowing chaos than implementing a concrete set of ideas on how the world's biggest energy producer should develop.
The problem is that they have no single programme, the 59-year-old leader told top members of his All Russia People's Front, an umbrella movement of supporters, at his presidential election campaign headquarters in Moscow.
They have many individual programmes, but no unified one and no clear way to reach their goals, which are also not clear, and there are no people who would be able to do anything concrete, Putin said.
Facing the biggest protests since he rose to power in 1999, Russia's most powerful politician has looked out of touch in recent weeks, dismissing thousands of protesters as chattering monkeys while offering gradual political reforms.
With supporters, Putin took the protests more seriously, saying his opponents deserved respect despite their hunger for what he termed Brownian motion, the apparently random movement of particles observed by Scottish scientist Robert Brown.
Putin presented himself as a leader able to ensure stability and protesters as spoilers bend on chaos, a potentially appealing strategy in a country which has been racked by crises and political chaos since the 1991 fall of the Soviet Union.
Putin, who polls show is Russia's most popular politician, said that he had a solid agenda which included modernisation of the $1.9 trillion economy and strengthening of defence.
He said protesters were trying to undermine the legitimacy of the parliamentary vote and called for a transparent presidential election.
When this kind of situation emerges, there is always an attempt to devalue and undermine the legitimacy of everything that happened in the public sphere, including and, most of all, the electoral process, he said.
Therefore, everything must be done in order to ensure that elections are understandable, transparent and objective.
Putin said his government would spend $500 million to install web cameras at all polling stations, an idea he first aired on December 15, although some of his supporters argued it would do little to boost transparency.
The gulf between Putin and tens of thousands of people who came out onto the streets of Russia's biggest cities has stoked speculation that Putin may seek to ditch some senior aides.
The Kremlin's powerful first deputy chief of staff, Vladislav Surkov, did not attend Putin's meeting, the first such absence for months at a meeting of such importance. Surkov did not return calls.
Other Putin's allies, including trade union activists, industry workers and war veterans, complained to their boss about the methods used by the opposition, with some calling for tighter Internet regulation.
I am outraged by what is happening on the Internet, said retired metal industry worker Valery Yakushev, referring to derogatory comments about workers who expressed their support for Putin which have been circulating on the web.
(Writing by Guy Faulconbridge; Editing by Maria Golovnina)