Yabloko is holding a congress in Moscow on June 21-22 to elect new leadership. The party is expected to replace deputy leaders with secretaries to be responsible for specific projects and have a greater say in decision making.
Speaking at the congress, Grigory Yavlinsky said the new governing structure would promote internal dialogue and help consolidate the party.
However, Yavlinksy reiterated his opposition to cooperation with political forces he considers too radical, as it contradicted Yabloko's program and could damage its public image.
"Yabloko is a democratic opposition party, not a nationalistic, criminal or Nazi one," he said.
The statement came amid a rift between Yavlinsky and his allies and the head of the party's St. Petersburg branch, Maxim Reznik, who has long campaigned for creating a strong coalition with other opposition forces to counter the dominance of pro-Kremlin parties on the political landscape.
Yabloko's 29 members were reported to have joined the opposition alliance comprising ex-world chess champion Garry Kasparov's United Civil Front, the outlawed National Bolshevik Party led by controversial writer Eduard Limonov, a Communist political movement and an array of opposition politicians.
Yabloko's alliance discussions with another liberal party, the Union of Right Forces (SPS), in recent years have foundered. Both parties have lost representation in parliament.