Navalny, who recently had his jail term extended, warned he expected high levels of fraud in the upcoming elections and that the Moscow mayoral elections had "no meaning" at all."Strategically, we see Smart Voting and its participants as the opposition's greatest asset and best opportunity," he said.Smart Voting was a strategy devised by the opposition in previous elections to galvanize and coordinate support behind candidates not from the ruling party.Since Russia launched full-scale hostilities against Ukraine last year, authorities in the country have intensified their crackdown on critical voices.Dozens of opposition activists have fled the country, and on Friday a Russian court placed the co-chair of independent election monitoring group Golos in pre-trial detention for at least two months.