President Dmitry Medvedev discussed threats of possible electioneering during the upcoming regional and federal elections at a meeting with leaders of the four State Duma factions in Sochi on Saturday.
He asked the parties to inform him of violations, which the opposition said include shady registration refusals for candidates as well as various tricks to hinder their campaigning.
Communist candidates faced "pressure, threats and blackmailing" during registration, deputy party head Ivan Melnikov said, Interfax reported.
"In our party, 20 percent of all candidates were denied registration, while [the ruling] United Russia has only six percent," Melnikov said, adding that elections commissions often employ "double standards" in their work.
Liberal Democratic Party chief Vladimir Zhirinovsky complained about campaign banners being removed from the streets under the pretext of making space for prioritized social advertising.
But the removed political banners are often not reinstalled, Zhirinovsky said.
Medvedev asked the parties to file complaints with his administration in case elections commissions refuse to cooperate.
Communist Party leader Gennady Zyuganov also said the president advised that the parties act on their own, without waiting for him to get involved. But Zyuganov did not elaborate on proposed measures.
Head of United Russia's Duma faction, Boris Gryzlov, said Saturday that the opposition parties were just preparing to account for their upcoming failure.
Twelve regions will elect local legislatures on March 13, the last big vote before the State Duma elections in December.