Bloomberg: Putin’s election grip is so tight even his nemesis can take part

The last time Vladimir Putin’s political party won national elections, ballot-stuffing allegations sparked the biggest protests of his rule.

Five years on, Putin appears to be so confident in his hold on power that even his most dogged adversary is welcome to challenge United Russia in next month’s parliamentary polls -- Mikhail Khodorkovsky, the London-based former oil billionaire who was charged with murder in absentia in December.