Jailed former tycoon Mikhail Khodorkovsky said Monday that Vladimir Putin's return to the presidency next year would increase tension with the West and close the door on a peaceful transition of power.

Putin, a former president who is now prime minister, and President Dmitry Medvedev have both hinted that they will run in next year's presidential election, but have said they will decide between themselves who will stand.

Khodorkovsky said Putin's return to the country's top job would turn back the clock and consolidate the grip on power by Putin and his circle made up mostly of former security agents, and make their removal impossible except by force.

"If Putin runs in the elections, this would mean that the peaceful transition of power has failed," he said in written comments published on Monday by the political weekly Kommersant-Vlast.

A single candidate is likely to emerge by the end of this year, closer to the parliamentary election in December.

Khodorkovsky, 47, former head of what was Russia's biggest oil firm, Yukos, was sentenced last December to remain in jail until October 2017 in a ruling seen as politically motivated by Putin's critics.

A poll by Levada, an independent polling center, showed on Monday that 34 percent of Russians believed there could be public unrest and an overthrow of the government, as had occurred in Egypt.

Putin served as president from 2000 to 2008 and created a power base in the Kremlin and among business leaders. His successor Medvedev, whom he steered into office in 2008, has focused on the need for reform and improvement of the rule of law.

Khodorkovsky said Putin's return to the Kremlin would aggravate confrontation with the West following the easing of tension with both NATO and the United States in the past two years.

Putin's return "would mean that the choice has been made toward limited confrontation with the West," he said.

Russia and NATO have agreed to cooperate on missile defense, while Moscow's ties with Washington have been "reset," boosted by a landmark nuclear treaty that committed the world's top two nuclear powers to reduce their atomic arsenals.

Khodorkovsky was first convicted of fraud and tax evasion in 2005 after running afoul of the Kremlin by funding opposition groups and speaking out against widespread, high-level corruption.