Oleg Morozov, deputy speaker of the State Duma, parliament's lower chamber, said: "It is quite clear that in order to obtain a simple State Duma majority, the party must win more than 40% of votes."
He said United Russia would analyze the March 12 elections to legislatures in various regions across Russia to eliminate mistakes in campaigning.
United Russia polled more votes than any other political party in the regional elections, touted by many as a dress rehearsal for State Duma elections in 2007.
"United Russia will have at least 50% plus one seat in all legislatures where the elections were held," Morozov said.
He added that single-constituency candidates had contributed a great deal, where party-list candidates had failed to secure an unqualified victory. United Russia's average results in the recent elections were higher than in State Duma voting in December 2003, when United Russia won about 37% of votes.