President Dmitry Medvedev on Friday submitted a bill to the State Duma that would return the threshold to win Duma seats to 5 percent from the current 7 percent, the Kremlin said.
Medvedev suggested in an interview published Friday that the threshold could be lowered further.
"All political forces that have significant popular support should be represented in the parliament," Medvedev told Moskovskiye Novosti.
"It does not mean that fringe elements should be present in the Duma as well. This is why we have the barrier," he said. "But 7 percent is too much, while 5 percent is a more realistic threshold. If that is too much we will make it 3 percent."
But opposition parties said the proposed change was only cosmetic because it would not apply to Duma elections this year but only to the next vote in 2016.
"What delight can we have in this extended carrot if it doesn't apply to the upcoming elections?" said Vladimir Ryzhkov, a co-leader of the Party of People's Freedom, or Parnas, which was denied registration to run in the elections by the Justice Ministry earlier in the week.
"Medvedev is just making a gesture to play down Western criticism, in particular concerning the denial of registration for Parnas," Ryzhkov said.
Yabloko leader Sergei Mitrokhin called the bill "a cosmetic change" and noted that whoever was elected president next year could cancel it.
Duma deputies largely supported Medvedev's initiative, Itar-Tass reported. "I think that the president's idea is rather rational," senior United Russia Deputy Oleg Morozov was quoted as saying.
Only four parties passed the 7 percent threshold in the last elections, in 2007, but several others came near the threshold or at least topped the 3 percent barrier to reclaim the 60 million ruble ($2.4 million) deposits that they paid to register to participate in the vote.
Then-President Vladimir Putin oversaw the raising of the 5 percent threshold to 7 percent in 2005.
Also in the newspaper interview, Medvedev indicated that he will create or lead his own political party.
"Not only I do not rule it out but I think that sooner or later it will happen. What party will it be? Allow me to refrain from answering this question," Medvedev said.
Putin leads United Russia, although he is not a member. Medvedev is not associated with any party.