The opposition Other Russia coalition group says it plans to hold a March of Dissent gathering in Moscow's Triumfal'naya square today, RFE/RL's Russian service reports.
The Moscow mayor's office has refused permission for the gathering, saying that a public event is to take place in the square.
But one of the coalition’s leaders, Eduard Limonov, told RFE/RL the gathering would take place regardless.
Limonov said the aim was to remind authorities about Article 31 of the constitution, which gives all citizens the right to hold mass gatherings and assemblies.
He said similar events were planned for the last day of every month.
A member of Other Russia's executive committee, Aleksandr Averin, told RFE/RL that the city authorities' refusal to allow the gathering was illegal.
Prominent Russian rights activists Lev Ponomarev -- the leader of the For Human Rights movement -- and Lyudmila Alekseyeva -- the chairwoman of Moscow's Helsinki Group -- told RFE/RL they planned to take part in the march as observers.