Former Russian Prime Minister Mikhail Kasyanov has said that Russia is backtracking on democracy.
Kasyanov was seen as an apolitical technocratic premier
He told a news conference in Moscow he might run for president in 2008 when the second term of incumbent Vladimir Putin expires.
He also said that Russia urgently needed a united liberal opposition.
Mr Kasyanov headed the Russian government throughout Mr Putin's first term, but was dismissed without explanation a year ago.
Many analysts linked his sacking to the disagreement over the clampdown on Russia's largest oil company, Yukos, and the imprisonment of its main shareholder, Mikhail Khodorkovsky.
Mr Kasyanov said that since his dismissal the country's course had changed. "It is the wrong vector, which negatively affects the social and economic development of the country," he said.
Asked about his presidential ambitions, he said that "everything is possible" and added:
"It is not important who will come to power in 2008. It is important that this person become the leader of the movement towards democratic values".
Some analysts have compared Mr Kasyanov to the new, pro-Western Ukrainian leader Viktor Yushchenko - who was also seen as a loyal technocrat as a prime minister.
Russian liberals have been in disarray since their defeat in the December 2003 parliamentary election.
The constitution does not allow Mr Putin to run for a third term.
Many analysts say he is likely to name Defence Minister Sergei Ivanov - who is regarded as a hardliner - as a successor.