If Vladimir Putin thought locking up Alexei Navalny would silence his most vocal domestic critic, Russia’s president was swiftly proved otherwise.

Less than 24 hours after Mr Navalny was sentenced to 30 days in jail and threatened with years more, his supporters hit back by publishing a two-hour-long video investigation that alleged a coterie of oligarchs had funded the construction of a lavish palace for Russia’s president on the country’s Black Sea coast, complete with indoor ice hockey rink, theatre, casino and secret tunnel to the beach.

The investigation, which has been viewed more than 37m times since Tuesday afternoon, was a stark reminder of the threat that the anti-corruption campaigner poses to Mr Putin’s regime. And it also allayed fears that the 44-year-old’s team of investigators and community organisers could be cowed or discombobulated by the detention of their leader.

Mr Putin’s iron-like grip on the levers of Russia’s skeleton democracy means Mr Navalny’s operation will struggle to make electoral inroads. But the charismatic campaigner’s ability to stir up popular outrage at examples of alleged government corruption and mobilise tens of thousands in street protests has long represented a major challenge for the Kremlin.

Attempts to sideline him through temporary detention, criminal cases and — according to Mr Navalny and a number of western governments — an assassination attempt in Siberia using the nerve agent novichok last August have all failed.

However, this week’s arrest, on charges of breaching the terms of a suspended prison sentence, that could see him sentenced to a total of three and a half years behind bars, is set to test just how popular Mr Navalny and his team are among ordinary Russians, and whether his incarceration will smother his movement or prove a rallying call against Mr Putin’s 21-year regime.

“Navalny now is not just a physical person, Navalny is somehow a movement: with its values, regional infrastructure and activists,” said Tatiana Stanovaya, founder of Russian political consultancy R. Politik. “So if the Kremlin just puts Navalny in prison and does nothing else, it will make the work of [his team] more difficult but will not stop it.”

In a message to his followers recorded shortly before he was taken to Moscow’s notorious Matrosskaya Tishina prison on Monday, Mr Navalny urged his supporters to protest on Saturday. The Kremlin has suggested this would be in breach of Russian law, and Moscow’s mayor has rejected an application for a public gathering, raising the possibility of clashes between police and protesters.

A heavy-handed attempt to suppress protests, combined with the arrest of Mr Navalny and dozens of his supporters this week, may mark the beginning of a renewed crackdown on opposition voices. That comes as the Kremlin gears up for critical parliamentary elections in September, with the ruling United Russia polling at historic lows, thanks to a moribund economy and falling real incomes.

“The use of chemical weapons against — and the subsequent detention of — the Kremlin’s most prominent critic Alexey Navalny . . . suggest[s] an increasingly restrictive civic and political environment in Russia ahead of the September State Duma election,” said Andrius Tursa of Teneo, a political risk consultancy.

The Kremlin has denied any role in the attacks on Mr Navalny and claimed he could have been poisoned outside Russia. It has also denied that Mr Putin is the beneficial owner of the Black Sea palace.

Late last year Mr Putin signed new laws that could be used to target political opponents and those who support, or are supported by, Mr Navalny’s organisation, by branding them “foreign agents”. This is a term loaded with espionage connotations and which carries with it serious bureaucratic and legal ramifications.

Vyacheslav Volodin, chairman of Russia’s parliament and a close ally of Mr Putin, on Tuesday told the chamber that Mr Navalny “is backed by foreign special services”, while Gennady Zyuganov, leader of Russia’s Communist party, claimed he was sent back to the country to incite insurrection. Vladimir Zhirinovsky, leader of the nationalist Liberal Democratic party, called for him to be banished to “the northern tundra, where birds freeze and fall to the ground mid-flight”.

The Communists and Liberal Democrats are members of the “systemic opposition”, who officially do not caucus with United Russia but receive support from Mr Putin’s regime and almost always support Kremlin policies.

“I don’t regret coming back . . . I refuse to put up with the lawlessness perpetrated by the authorities of my country,” Mr Navalny wrote in an Instagram post from prison on Tuesday.

“The scoundrels in the Kremlin . . . divide us into three columns: those who are silent; those who understand but are silent; and those who refuse to be silent and fight,” he wrote. “The third column scares them . . . I urge everyone to choose the right column.”

Mr Navalny is boycotted by state-controlled and Kremlin-friendly television channels, and Mr Putin does not speak his name. State propagandists dismiss him as unknown or detested outside liberal Moscow circles.

Yet research by the Levada-Center, an independent pollster, in September found that 20 per cent of Russians support Mr Navalny’s actions, even if his overall public trust rating — at about 4 per cent — was far below Mr Putin’s 33 per cent.

With him in jail, attempts to close that gap will rely mainly on the continued work of his community organisers spread all across Russia’s regions, and the anti-corruption researchers, some of whom are crucially based overseas.

“The Kremlin demonstrates very hardline intentions,” said Ms Stanovaya. “So the question is whether the Kremlin will opt for steamroller tactics? It seems to me rather logical.”

“[They] can really suppress regional infrastructure; hamper the work of Navalny’s team in Russia, as well as impeding the spread of the investigations in social media and on the internet in general, including YouTube,” she added. “But what they can’t do is to hamper work for those investigators who are abroad.”