"We expect this to be a political and public event, without outrage, but with specific demands," Nikolai Alexeyev said, speaking on the Ekho Moskvy radio station.
Moscow authorities rejected official requests by Gay Parade organizers in 2006 and 2007 for permission to march, on the grounds that it would interfere with the rights and routines of ordinary Muscovites.
Mayor Yuri Luzhkov has branded gay pride parades "Satanic" and vowed that they would never be permitted in the capital, while the Russian Orthodox Church and various far-right groups have sworn to halt any attempt to hold a march in support of gay rights in Russia.
Alexeyev said: "If the march will be again illegally banned, we will apply to Russian and European courts."
Last year, Moscow's Tverskoi District Court ruled that a city ban on holding a Gay Pride Parade was legal. Around 100 protestors subsequently gathered outside City Hall to submit a petition to the mayor against what they called an 'unfounded and illegal prohibition on holding the march in support of sexual minorities in Russia.'
The protest turned violent when a British gay rights activist was kicked and beaten by extremists, and police detained 31 people, including two Italian members of the European parliament, in the ensuing melee.
Homosexuality was legalized in Russia in 2003, but discrimination against gays and lesbians remains widespread. The hostile crowd during the 2007 May demonstration included people carrying crosses and wearing Orthodox Church dress, along with ultranationalists.
Russia is a member of the Council of Europe, and a signatory to the European Convention of Human Rights, which obliges the state to allow demonstrations to be held.