President Putin’s announcement that he would like to become prime minister is a coup de théâtrefor which this shrewd political operator is justly famous. For months speculation over his future has obsessed Russia. He has insisted repeatedly that, after he leaves office in March, he wants to continue serving his country in some capacity. How he would do so has always been unclear, however. Would he take the job as head of Gazprom, the vast state energy monopoly that is so vital to Russia’s future? Would he revitalise the job of National Security Adviser? Or would he become a roving ambassador, holding no official post but exercising influence behind the scenes as Deng Xiaoping did in China?

In a recent conversation with The Times and other Western reporters and academics, Mr Putin made it very clear that he had no intention of leaving the political scene. He made it equally plain that he would not change the Constitution, but would retire, as required, in March. He did not rule out returning as president in 2012 - though tried to downplay this scenario. But he insisted Russia must still have a strong president, as its parties were still too undeveloped to play the role they do in Western democracies.

His remarks suggested an impossible contradiction. How could any successor be a strong president if Mr Putin was still very much in the political arena? Speculation within Russia has been increased by his unexpected reshuffle of the Government, three months before parliamentary elections, and the appointment of the elderly and relatively unknown Viktor Zubkov as Prime Minister. Mr Putin insisted this was to ensure that all the Government kept working properly until the final day. Most Russians assumed, however, that Mr Putin was either grooming Mr Zubkov as a future, pliable president – or that he was deliberately keeping in play the two deputy prime ministers and likely contenders for the top job, Sergei Ivanov and Dmitry Medvedev, so as not to make a preference known that would inevitably make him a lame duck president.

Mr Putin had already dismissed the idea of becoming prime minister himself. Several things, however, may have changed his mind. The first is that the pressure on him to make an announcement has become intense. And it is increasingly clear that there is no other job that would give him the power and properly defined responsibility that he craves. Secondly, with popularity ratings running at about 80 per cent, there is a danger that his supporters and those who have enriched themselves during his reign will be so fearful of change that they stage a crisis to force a change in the Constitution and Mr Putin’s continuation in office. Thirdly, his wish, real or assumed, to build up the party system and turn United Russia into something more than just a vehicle to bolster his power meant that he would have to declare his intentions before the party holds its extraordinary congress this month to decide who to head its list for the Duma elections.

The effect will be to reverse the power balance between the president and prime minister. It underlines the weakness of Russia’s democracy and constitution, which must still bend to the dominant personality. Russians have lauded the economic benefits of a Putin presidency, but may well have cause to regret his impact on a still-emerging democratic system.