JOIN USPreliminary results showed United Russia with commanding leads in each of the 12 local legislative elections in a vote that both the losing Communist Party and independent observers said was riddled with fraud.
United Russia rides the coattails of its chairman and Russia's former president Vladimir Putin and already includes the vast majority of the country's political elite.
The party's leader in parliament -- where it can pass Kremlin legislation without anyone else's backing -- said the results showed that United Russia's dominance was here to stay.
"This tells us that the country's political system... works in the voters' favour and that they trust it," Boris Gryzlov said in statement posted on the party's website.
"I would like to thank all the voters. This is both an evaluation of the party, (a sign of) support for the authorities, support of the president and support for our party leader Putin," he added in televised remarks.
United Russia was further boosted by figures showing turnout of about 50 per cent -- higher than previous local elections. Its best showing of 71.1 per cent came in the Far Eastern Chukotka region.
The results flew in the face of polls indicating lower levels of support for a party that in November was personally condemned by President Dmitry Medvedev for "showing symptoms of stagnation".
The respected Levada Centre said in a February survey that support for United Russia started falling in early 2009 and stood at 35 per cent in January.
The state-controlled media has recently highlighted a series of corruption scandals involving United Russia officials. Surveys had suggested that voters' resentment was also growing because of rising food prices.
Communist Party boss Gennady Zyuganov called the polls the most fraud-riddled in Russia's post-Soviet era.
"We witnessed United Russia using all the dirty tricks invented in the past 15-20 years," Interfax quoted Zyuganov as saying. "This ugliness did not exist before."
The Communist Party had its best showing in central Russia's Nizhny Novgorod region where it looked to be placed second with about 29 per cent of the vote.