Russia's Vladimir Putin seeks 4th term as president

Mr Putin has been in office - either as president or prime minister - since 2000, and a win next year would see the 65-year-old extend his dominance of the nation's politics into a third decade.

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

"There's no better place or opportunity to put my candidacy forward. I'm sure that everything will work out for us."

Past candidates such as Communist chief Gennady Zyuganov, ultranationalist Vladimir Zhirinovsky and liberal leader Grigory Yavlinsky have all declared their intention to run.

Ksenia Sobchak, a TV host who is the daughter of late former St Petersburg mayor Anatoly Sobchak, who was Putin's boss in the 1990s, is also likely to join the field.

Alexei Navalny, the most prominent Putin opponent, also wants to run, even though a conviction he says is politically motivated prevents him from joining the campaign.

Mr Putin's approval ratings top 80%, meaning a comfortable first-round victory in the March poll is likely.

A win would see Mr Putin secure a fourth six-year term as president and means he would be eligible to serve until 2024, when he will be 72.

Mr Putin is lauded by supporters as a strongman figure who has restored national pride and given Russia a renewed clout on the international stage.

But opponents say he has overseen a corrupt authoritarian system and accuse him of destabilising the world order through Moscow's interventions in Syria and Ukraine.

Analysts note that Mr Putin's biggest challenge in the election will not be fending off his opponents - no one appears capable of beating him - but rather mobilising voters to turn out amid signs apathy is seeping in.

While a Putin victory is seen as a safe bet by most Russia watchers, what follows next is likely to be more unpredictable.

A fourth term would be, under Russia's constitution, Mr Putin's last and there is no obvious successor on the horizon.

Many investors say the lack of a clear succession plan and the jockeying for position that is likely to ensue as the Putin era comes to an end is becoming the biggest political risk.