Russian President Vladimir Putin said Wednesday he'll seek re-election in March 2018, and opinion polls indicate he would comfortably win, setting the stage for him to extend his dominance of Russia's political landscape into a third decade.

"I will put forward my candidacy for the post of president of the Russian Federation," Putin told an audience of workers at a car-making factory in the Volga city of Nizhny Novgorod.

Putin, 65, first became president in 2000. Because of laws limiting presidents to two consecutive terms, he ceded the presidency to Dmitry Medvedev from 2008-12, but effectively retained overall power while serving as prime minister during those four years.

During Medvedev's time as the titular leader, subsequent presidential terms were lengthened from four to six years, meaning the next term would see Putin through until 2024.

Television host Ksenia Sobchak has officially registered for next year's election, although her candidacy has been dismissed as giving the illusion of competition.

Sobchak said on Wednesday that Putin would probably win "as always," but that she still planned to run to represent people who wanted change.

Otherwise, Communist leader Gennady Zyuganov, 73, and nationalist firebrand Vladimir Zhirinovsky, 71, are likely to run. They are broadly supportive of the Kremlin's policies and have repeatedly run for president, behaviour critics say is a ruse to create the illusion of genuine political choice.

Russia Opposition-Navalny

In this July 2017 file photo, Alexei Navalny arrives at his office in Moscow, Russia. Navalny, a popular opposition figure, will likely be barred from running against Putin in 2018. (Pavel Golovkin/Associated Press)

Popular opposition figure and Putin critic Alexei Navalny has held anti-corruption rallies across the country and is popular with many young Russians. The 41-year-old would like to run in the election, but he has been ruled ineligible by the country's Central Election Commission due to past criminal charges that Kremlin critics have suggested have been trumped up.

"He wants to be in power for 21 years," Navalny wrote on social media shortly after Putin declared his intentions on Wednesday. "To my mind, that's too long. I suggest we don't agree."

Putin successor open to question

Putin is lauded by allies as a father-of-the-nation figure who has restored national pride and expanded Moscow's global clout with interventions in Syria and Ukraine. His critics accuse him of overseeing a corrupt authoritarian system and illegally annexing Ukraine's Crimea, a move that has isolated Russia. 

Putin draws much of his support from outside the two biggest cities — Moscow and St. Petersburg — where many credit him with raising their living standards despite an economic crisis Russia is only now recovering from. As well, he receives uncritical coverage from Russian state television.

While next year's election in March is devoid of real suspense about who will win, what follows is more unpredictable as attention will turn to what happens after Putin's final term — under the current constitution — ends.

There is no obvious successor, and many investors say the lack of a clear succession plan, and likely jockeying for position among Russian elites for dominance in the post-Putin era, is becoming the biggest political risk.

If re-elected next year, Putin would have to choose whether to leave Medvedev as prime minister or appoint someone else. That decision would trigger a round of intrigue over the succession, as the person who holds the prime minister's post is often viewed as the president's heir apparent.

With files from CBC News