Moscow authorities have agreed to allow a large-scale opposition rally at the weekend, the latest in a wave of protests against President Vladimir Putin that have swept Russia since December.
An official at the city hall's security department confirmed that an agreement was reached to hold a rally and march in the capital on Saturday. Similar protests are planned in most of Russia's large cities.
Protesters will gather in Moscow's central Pushkin square and walk along the boulevards to Sakharov avenue, the official told AFP, declining to give his name as the agreement still had to be signed by the deputy mayor.
The rally comes amid a crackdown against protesters following clashes during a similar event in May. A probe into "mass riots" on Moscow's Bolotnaya square already resulted in pre-trial detention for a dozen people.
Opposition leader Sergei Udaltsov, who was one of the people involved in negotiations with the authorities over several days, called on supporters to attend what he has termed the "March of Millions" on his Twitter blog.
"The city hall cut down the number of people to 25 thousand (from 50 thousand). I don't see a problem, we are prepared to pay a fine for surpassing the amount," he tweeted jokingly.
Over 4,000 people registered as going to the event on Facebook on Wednesday. Rallies have also been sanctioned in Russia's second-largest city of Saint-Petersburg and several regional cities like Krasnodar in the south.
In what could potentially draw even larger numbers to the street, the Communist party said it will participate in Saturday's rally, for the first time since party leader Gennady Zyuganov criticised the liberal protests.
"We made a decision to participate in the March of Millions," the head of the Communist fraction in the Moscow city parliament, Andrei Klychkov, wrote on his Twitter site.
Russia's opposition has staged a series of large-scale anti-Putin protests in Moscow since the December parliamentary polls which many people consider rigged.
The last rally in June drew around 50,000 people, according to organisers, and followed about the same route as the rally scheduled for the weekend.