MOSCOW, RUSSIA - SINCE the fall of the tsars, Russians have known the Kremlin as the seat of ultimate power. From Wednesday, they won't be so sure.

Mr Vladimir Putin is to hand control of the fabled fortress to president-elect Dmitry Medvedev in a solemn ceremony before assuming the less august position of prime minister the following day.

But despite the apparent demotion, Mr Putin is widely expected to take much of his power with him to his new office in the White House, a hulking Soviet building four kilometres from the Kremlin.

As the country's top bureaucrat, Russia's prime minister has always been subservient to the president, who has the power to dismiss the government on a whim.

But two-thirds of Russians believe prime minister Putin and his allies will instead control president Medvedev, turning the traditional power structure on its head, according to an April poll by the Levada Centre.

Even the best-connected Kremlinologists have been left guessing how the two old friends might split power, said Masha Lipman, a Russia expert with the US-funded Carnegie Centre.

'All we can be certain of is that Putin will be more powerful than any prime minister before him,' she said. 'Beyond that, no one knows what is going to happen. It's a matter between the two men.'

In a February speech, Mr Putin described the prime minister's office as the 'highest executive power in the country.'

The presidency, he indicated, was a more symbolic post as 'guarantor of the constitution.'

The remark was widely seen as preparing the ground for a change of definition for the presidency, in which Mr Putin took on unprecedented powers over the last eight years.

Last month Mr Putin bolstered his base by taking control of the country's dominant party, United Russia, whose two-thirds majority in parliament gives it the power to change the constitution.

This would allow Mr Putin to 'redistribute powers and transform Russia into a parliamentary republic' if there was a stand-off with the presidency, said Mr Sergei Markov, a member of parliament for United Russia and a pro-Putin political analyst.

In recent weeks Mr Putin has moved to transform the prime minister's office, boosting its staff by 50 per cent, bringing in close allies from the Kremlin and reducing the technical issues that clog up the cabinet agenda.

In a sign of his attachment to the presidential lifestyle, Mr Putin has been allowed to keep his Novo-Ogaryovo residence in an elite suburb west of Moscow.

While pundits agree that a major shift of influence to the prime minister's office is underway, not everyone sees a simple power-grab by Mr Putin, who was barred by the constitution from running for a third presidential term in March.

Dual leadership system
The dual leadership system is seen by some as a careful mechanism allowing Mr Putin to control the transition.

'For Putin, power is a burden,' said Mr Markov, who heads the Moscow-based Institute of Political Studies as well as serving in the lower house of parliament, the State Duma.

'If Medvedev follows Putin's policies better than Putin himself, then Putin will step aside.'

But if Mr Medvedev proves too weak, his presidency could be reduced to a role akin to a foreign minister - and he could be forced to step down at the end of his first term in 2012, Mr Markov said.

The constitution bars anyone from holding the presidency for more than two terms in a row, but that would not stop Mr Putin standing again in 2012.

Other observers believe that as the country's most powerful institution, the presidency will prove less malleable than others, such as the parliament, which mr Putin managed to tame during his presidency.

Once Mr Medvedev takes his place in the Kremlin, no one will be able to control him, said Mr Alexander Konovalov, the director of the independent Institute for Strategic Assessments.

'No one in Russia has ever managed to bind the hands of someone with such enormous power,' he said, giving the example of Soviet leader Leonid Brezhnev who was chosen to rule the Soviet Union in 1964 because he was seen as the weakest candidate.

'He ruled from the Kremlin for 18 years,' he said. -- AFP