United Russia wants to turn the State Duma elections into a political coup to prolong President Vladimir Putin's rule, Communist Party leader Gennady Zyuganov said.

He warned that any attempt by Putin to hang on to power when he steps down as president in May could result in turmoil.

In an article published Friday on the party's web site, Kprf.ru, Zyuganov attacked a statement by United Russia that described December's elections as a "national referendum in support of Vladimir Putin."

"The Dec. 2 vote is a vote for Putin," United Russia leader Boris Gryzlov said in the statement published by the government daily, Rossiiskaya Gazeta, on Wednesday. "Vladimir Putin will remain the national leader whatever post he holds."

Putin, who is coming to the end of the second of two consecutive presidential terms allowed by the Constitution, has refused to reveal his plans.

But he has said he intends to remain in politics to make sure his successor sticks to his policies.

Earlier this month he agreed to head United Russia's party list, positioning himself as an informal leader of the party sure to win the majority of seats in the Duma but also hinting he could become prime minister.

"The election is not a referendum," Zyuganov said in an attack on Gryzlov, who suggested that Putin could continue ruling Russia from a parliamentary power base. "Such an interpretation violates the Constitution."

"Gryzlov's article is, in fact, a manifesto for an authoritarian coup," he added. "Only authoritarianism allows a situation when a person has dictatorial powers without holding the top official post." United Russia is expected to win more than 60 percent of the vote in the elections, while the Communists are likely to come second with 17 percent.