It's another fake story by Putin's team.
They will do anything possible in order to stop Navalny, only real opposition in Russia now.
We know that there is no democracy or freedom in Russia, so no way that Putin can loose any election.
Putin comes from the intelligence circle and knows how to manipulate people and increase his power.
Putin using all possible methods, legal and illegal, to increase his power and wealth.
He can't afford to lose power because for him it means the loss of freedom and jail.
So, he will use any possible media manipulation in order to stop others, possible political rivals.
Navalny is one of the "real" opposition figures, unlike the "compromised" opposition leaders such as Zhirinovsky and Zyuganov. But that said, his popularity ratings are no way near that of Putin. More people dislike him, than those who like him. Loot at the Moscow mayoral elections of 2013. He managed to win just 27.24% of the vote, despite the Western observers certifying the elections as free from voter fraud and intimidation.