Federation Council Chairman Sergey Mironov has launched a counter-attack on the United Russia party after it demanded his resignation.
The pro-Kremlin United Russia party was angered by Mironov's criticism of Prime Minister Vladimir Putin's policy.
"Do members of United Russia think that opposition and criticism are dishonest?" Mironov asked. "In a civilized society this is the duty and goal of the opposition," he told journalists.
Mironov, the head of the small party A Just Russia, also loyal to the Kremlin, fueled the wrath of the United Russia party on Monday when he said in a television interview he did not fully share Putin's policy.
"Our party supports everything related to foreign and some domestic policies; however, we absolutely disagree with the budget plan introduced by Vladimir Putin," Mironov said. "We disagree with the anti-crisis measures that Vladimir Putin introduced, this is why we proposed our anti-crisis plan."
Senior members of the United Russia party, which holds the parliamentary majority and is led by Putin, said they were planning to demand Mironov's resignation.
"Considering that he [Mironov] represents St Petersburg's legislative assembly, where we [the United Russia] have the majority, I believe it is logical and necessary ... to initiate resignation procedures," said Andrey Vorobev, head of United Russia's central executive committee.
Vyacheslav Volodin, a leading member of the United Russia party, said Mironov's remarks showed his "dishonesty and inconsistency with regard to Vladimir Putin - a person who has done so much for the country and its people".
Mironov described the United Russia party's reaction as "panicky and hysterical".
He said his resignation is possible only at the request of his fellow members of the upper house.
"If my colleagues are not happy with my work they can raise the question of my resignation at any meeting of the supreme chamber," Mironov said.
Russia was badly hit by the global economic crisis, with the Russian government devaluing the ruble and cutting spending. The government also introduced a set of unpopular measures in 2010, including higher utility bills, increased prices for food and medicines and higher public transport fares.
However, despite heavy criticism from opposition parties, the popularity of Putin and President Dmitry Medvedev has not been damaged by the crisis and they remain unchallenged leaders in opinion polls.
RIA Novosti