An online battle between one of Russia's richest men and its most prominent opposition politician is not going away.
Uzbek-born tycoon Alisher Usmanov issued his second YouTube attack on Aleksei Navalny in a week on May 24, rejecting his challenge to a public debate and calling him a "highly artistic liar."
The war of words between the Kremlin-connected magnate and one of President Vladimir Putin's most outspoken opponents comes ahead of a March 2018 election in which Navalny is seeking to run.
On May 17, Usmanov and Navalny exchanged bitter, strongly worded video salvos as they rejected a Moscow court's proposed settlement in a defamation case that the metals-to-media tycoon filed against the anticorruption crusaders.
Usmanov was back at it seven days later, issuing a new video in which he likened Navalny to one of the most unlikable figures in Russian literature: Poligraf Sharikov, the loutish dog-turned-man in Mikhail Bulgakov's 1925 novel Heart Of A Dog.
Usmanov called Navalny "not just an uneducated demagogue, but a highly artistic liar."
He noted that Navalny had declined to apologize for the report that prompted his defamation lawsuit and added: "We will meet in court."
Usmanov filed the suit against Navalny and his Anticorruption Foundation in April.
The defamation claim stems from a March 2 report by Navalny's foundation that focused on Prime Minister Dmitry Medvedev and included allegations that Usmanov gave expensive property to a foundation linked to Medvedev at no cost.
In his initial video, Usmanov -- whose words and manner evoked the image of Russian crime boss for many viewers -- called Navalny a "loser" and compared him to a "puppy barking at an elephant."
He also mock spit on Navalny, a reference from a popular Soviet-era film.
Navalny fired back with his own video, calling Usmanov "a beginning blogger" and "a bribe-taker, a bribe-giver, a crook, and a fraudulent man."
The court that is handling the lawsuit has scheduled a hearing for May 30.
Navalny was among the leaders of a wave of protests in 2011-12 and has irked the Kremlin with his reports alleging pervasive corruption in circles close to Putin.
He has been campaigning for the presidential election next March in which Putin is widely expected to seek and secure a new six-year term.
Russian authorities have suggested that Navalny will be barred from the ballot due to a conviction on financial-crimes charges that the opposition leader says were fabricated by the Kremlin.
But election officials have not stated clearly whether Navalny will be allowed to run, and he has pushed ahead with his campaign.