Two Russian opposition parties have agreed to unite ahead of parliamentary elections in 2016.
Joining forces will be RPR-Parnas, the party founded by the murdered opposition leader Boris Nemtsov, and Party of Progress, led by anti-graft blogger Aleksei Navalny.
In a statement issued on April 17, they called on the public and civic forces "to consolidate on a common platform of rejection of lies, corruption and aggression, suppression of economic and civil liberties and for building a democratic state in our country."
A former deputy prime minister, Nemtsov was gunned down in Moscow on February 27.
The Kremlin denies stifling dissent and President Vladimir Putin has urged law enforcement bodies to investigate the case in full.
Opposition activists led street protests in 2011 and 2012 but the rallies lost momentum as Putin started a third presidential term and tightened his grip on power.
Navalny and other critics of the Kremlin have faced court cases and convictions on charges they denounce as political, while other activists have been driven into exile.
Based on reporting by Reuters and BBC