The opposition in Ukraine is calling on supporters to turn out in force on December 17 in Kyiv.
The demonstration in the Ukrainian capital will coincide with a visit by President Viktor Yanukovych to Moscow for talks with Russian President Vladimir Putin, reports RFE/RL.
Demonstrators have been on the streets in Kyiv for nearly four weeks now, angry over a decision by Yanukovych to shelve a long-anticipated accord on closer ties with the European Union.
Ukraine's opposition fears Yanukovych will take the first steps to joining a Russian-led Customs Union when he sits down for talks with Putin.
Analysts say if Putin offers Yanukovych anything, it could be a mix of credit, investment pledges, and a discount on energy prices, particularly natural gas.