Thousands of demonstrators are to defy an official ban and take to Moscow's streets today to protest against President Vladimir Putin and his policies.
It will be the first organised public protest of its kind in the run-up to parliamentary elections next year and a presidential vote in 2008 that will see Mr Putin step down.
The protest, called "The March of Those Who Don't Agree," is being organised by a coalition of anti-Kremlin forces that includes liberal free marketers, nationalists, and radical youth movements.
Organisers include former world chess champion Garry Kasparov, former Prime Minister Mikhail Kasyanov, and Eduard Limonov, a radical nationalist whose own National Bolshevik party is officially banned.
Though the event's participants come from across the political spectrum, they are united by one thing: their opposition to Mr Putin and what they claim is his growing fondness for authoritarianism.
The coalition of political forces behind the event is called "Another Russia, " a group that has styled itself as the main opposition movement to the government despite its own fractured nature and its outsider status in the tightly controlled mainstream political arena.
"Another Russia's" leaders contend that the Kremlin is imposing draconian restrictions on political life.
In particular they take exception to a new law that gives the authorities a free hand to deal with anyone deemed to be "extremist" as well as legislation that makes it hard for smaller non-Kremlin aligned parties to stand in elections.
There are fears that today's rally could become violent since the Kremlin has strict rules for such demonstrations that it often enforces with brutal force.
Almost 9,000 policemen and troops have been drafted into the centre of Moscow for the rally including the OMON or riot police.
"Acting within the law (police) will decisively prevent and if necessary forcibly bring to an end any anti-social displays," it has been promised.
The authorities have forbidden protestors from marching down Tverskaya Ulitsa, Moscow's main thoroughfare, and confined them to two static rallying points instead.
But the event's organisers have said that their supporters will march between the two venues regardless and have conceded that things "could end badly."
They have claimed that their supporters have been intimidated ahead of the rally and that activists coming into the Russian capital from the provinces have been warned to stay away.
Earlier in the week Mr Kasparov's offices were raided by the FSB security service who confiscated material relating to today's protest.
But the former chess champion says he is refusing to back down.
"The Dissenters' March is the march of those who cannot and will not keep quiet any longer," he said in an appeal to Muscovites to attend. "The time has come to show will and responsibility."
Though today's rally is undoubtedly symbolically significant, the number of protestors is likely to be small by Russian standards and not number more than 5,000.
In contract the pro-Putin "Nashi" (One of Us) youth movement has promised to organise its own march tomorrow with 100,000 attendees.Reuse content