Mr Yeltsin moved to shore up his position by saying that the presidential campaign had not even started.

Presidential elections are due for the middle of 2000, but President Yeltsin's health problems have prompted speculation about a possible early poll.

Correspondents say that Mr Yeltsin's words were reminiscent of Soviet-era Kremlin leaders, as he left people guessing who he might be talking about.

They say he was most probably referring to the Mayor of Moscow, Yuri Luzhkov, who recently launched his own political movement.

Other leading presidential contenders are Communist Party leader Gennady Zyuganov, Governor of the Siberian Krasnoyarsk region Alexander Lebed, liberal politician Grigory Yavlinsky and the former prime-minister Victor Chernomyrdin.