Russians have begun voting in a presidential election set to give Vladimir Putin a commanding victory that could only be blemished if large numbers do not bother taking part because the result is so predictable.

On Russia’s eastern edge, in the Pacific coast city of Petropavlovsk-Kamchatsky, polling stations opened early on Sunday and voting across the vast country will run until polls close at the westernmost point, the Kaliningrad region, 22 hours later.

Opinion polls give Putin support of around 70 per cent, or nearly 10 times the backing of his nearest challenger. Another term will take him to nearly a quarter century in power — a longevity among Kremlin leaders second only to Soviet dictator Josef Stalin.

Many voters credit Putin, the 65-year-old former KGB spy, with standing up for Russia’s interests in a hostile outside world, even though the cost is confrontation with the West.

A row with Britain over allegations the Kremlin used a nerve toxin to poison a Russian double agent in a sleepy English town — denied by Moscow — has not dented his standing.

Pictures of candidates at a Moscow polling booth, with Vladimir Putin in pride of place. Photo: EPA/Yuri Kotchkov

The majority of voters see no viable alternative to Putin: he has total dominance of the political scene and the state-run television, where most people get their news, gives lavish coverage of Putin and little airtime to his rivals.

His nearest rival Pavel Grudinin, the Communist Party’s candidate, is on just seven per cent.

The first politician in years to challenge the Kremlin’s grip on power, Alexei Navalny, is barred from the race because of a corruption conviction he says was fabricated by the Kremlin.

He is calling for a boycott of the election, saying it is an undemocratic farce, and deploying supporters to collect evidence of anyone rigging the ballot to inflate turnout and support for Putin.

The Kremlin and election officials swear any fraud will be stamped out.

Kremlin officials privately acknowledge a worry that some of Russia’s 110 million eligible voters will not bother casting ballots because they believe Putin is a shoo-in. A low turnout would diminish his authority in his next term, which, under the constitution, has to be his last.