Russia will experience "a kind of Arab Spring" within two years if the winner does not initiate profound and swift political reforms, one of the main candidates fighting tomorrow's presidential election has warned.
Sergei Mironov (59) said Vladimir Putin was likely to be the next president but predicted he would face growing unrest if he failed to respond to protesters' demands.
"Russia today is like the Concordia liner," he said in an interview at his offices, "steaming on to the reefs while the captain tells those aboard, 'don't worry, everything is calm and normal.' But it's not normal and we need to set the ship on a new course."
Mr Mironov said: "Whoever wins the presidency, if he does not immediately begin deep political and social reforms, including a clearer articulation of our foreign policy objectives, my prediction is that Russia will be shaken by a kind of Arab Spring within two years."
Mr Mironov is a former ally of Mr Putin and it cannot be ruled out that he is raising the spectre of a revolution as a subtle way of endorsing a crackdown on street demonstrations that are expected in the days after the vote.
However, the ex-paratrooper had a serious falling out with Mr Putin's allies when he was ousted as chairman of the upper house of parliament in May last year and his once Kremlin-controlled party, Fair Russia, has ploughed a more independent furrow in recent months.
Mr Putin is expected to win the election easily. Some polls put him 50pc ahead of his closet rival, the communist, Gennady Zyuganov -- but he has been rocked by a series of mass street protests against his rule.
Analysts say these demonstrations, in response to Mr Putin's supporters crudely fixing a December parliamentary election in favour of his party, United Russia, show that Russians are no longer happy with the pact under which civil freedoms were ignored in exchange for rising prosperity.
In a meeting with foreign journalists this week, Mr Putin denied speculation he would use autocratic methods to stifle his opponents after the vote, pointing to a legal initiative by President Dmitry Medvedev that would ease restrictions on registering political parties.
He said: "We are not planning anything of the kind.
On the contrary, all our suggestions are intended to ensure dialogue with both those who support us, and those who criticise."
However, Mr Mironov, who has promised to hold early parliamentary elections if he wins, said: "Vladimir Putin believes that, yes, some cosmetic reforms are necessary, but he does not plan to make any fundamental changes."
Analysts link a rise in his ratings in recent weeks to promises of increased public sector salaries, and cheaper health care.
But this could backfire if oil revenues drop and it becomes tricky to balance the budget, possibly triggering unrest.
Mikhail Dmitriyev, a sociologist, said protesters were more concerned with justice and equality than social welfare.
Mr Putin's rule sticks in the craw of middle class Russians, he said, because nepotism and corruption crimp opportunity, while an arrogant elite is seen to flourish.
"Taking into account the deteriorating of his political brand, it is quite likely that Mr Putin will not be able to hold on until the end of his term," Mr Dmitriyev said.
Mr Putin refused to cancel the disputed parliamentary vote in December and Russia's rigid set-up, said Mr Dmitriyev, would prevent him from dousing discontent.
"The leftists demand a fairer distribution of wealth and greater social justice but the system is unable to satisfy their demands because corruption is an essential part of the crony capitalism that Putin created," he said.
"The current political framework is equally unable to cope with the demand of the urban middle class for rule of law: there is no democracy, the authorities are unaccountable."
Russian authorities talked of their fears this week of an uprising similar to the 2004 Orange Revolution in Ukraine, as the country braces itself for pro-Kremlin and opposition demonstrations tomorrow and Monday. Activists who tried to hand out tents in central Moscow were arrested on Wednesday.
In another sign of nervousness, Russian state television pulled a German documentary about Mr Putin due to be shown tonight .
The film is an intimate behind-the-curtain portrait which includes scenes such as Mr Putin trying to crush an ice hockey helmet on to his head, back-to-front.
However, Gleb Pavlovsky, a former Kremlin spin doctor, said last night that: "Putin's return was a tactical mistake. I said that it wouldn't be accepted, neither by the people nor by the elite."
But while Mr Putin is losing support, Mr Pavlovsky said his demise was not imminent.
"People no longer believe that Putin can be their guarantor, but if he can't, then who can?"
(© Daily Telegraph, London)