KIROV, a town 900km (560 miles) east of Moscow, is not known for its attractions. It was the place of exile for a 19th-century revolutionary, Alexander Herzen. On April 17th an army of journalists descended on Kirov for the biggest political show trial of the season. In the starring role was Alexei Navalny, a popular anti-corruption blogger and opposition figure who has an almost cult-like following among Russia’s internet-using middle class.

In the past three years he has united different camps, forcing the Kremlin to respond to his anti-corruption campaigns and his rising popularity. The case against Mr Navalny is part of the response. He is accused of embezzling $500,000 from a state timber company during his time as an adviser to the governor of Kirov.

The case began two years ago but local prosecutors dismissed it. Then Alexander Bastrykin, Russia’s chief federal investigator, ordered it reopened. (Mr Navalny had ridiculed him as a “foreign agent” and publicised threats made by Mr Bastrykin to a Russian journalist.) That the company from which the timber was stolen was paid and that Mr Navalny had no proven role in the transaction seem to be details. “If a person tries to attract attention or teases the authorities—‘look at me, I am so good compared to everyone else’—well then interest in the process of exposing him naturally speeds up,” a spokesman for Mr Bastrykin told a Russian newspaper.

The case has been adjourned for a week, but Mr Navalny has few doubts that he will be convicted. The question is whether he gets a sentence of up to ten years, or a suspended one that could become real if he is politically active. Since Mr Navalny told an internet television channel that he wants to be president and would do anything in his power to have Mr Putin and his cronies jailed, the gloves have come off.

The Kremlin takes Mr Navalny more seriously than any other opposition figure except Mikhail Khodorkovsky. Mr Navalny is a new type of politician, who does not come from within the system or have Soviet baggage. He has circumvented the Kremlin television monopoly by using social networks. He is smooth, has no clear ideology and few convictions; but he does have political intuition. He has manoeuvred between nationalists and liberals, before lighting on the one issue that galvanises both: corruption.

Mr Navalny’s main appeal is not to the Russian intelligentsia but to the urban, mobile middle class, small-time entrepreneurs and managers in private firms who flourished in the 1990s. Many voted for Vladimir Putin in 2000 but have become disenchanted and angry as state bureaucrats have encroached on their territory.

Mr Navalny sees politics as a full-time profession. As a minority shareholder in several Russian state firms, he sued them for more information, publicised details of odious state tenders and corrupt deals, and exposed many linked to Mr Putin. He has done more damage to the ruling United Russia party than anybody else. His branding of United Russia as “the party of crooks and thieves” has spread virally. And his call for people to vote for any other party in 2011 was so effective that, when United Russia tried to boost its poor results through ballot-rigging, people came out with him in protest.

Over the past two years Mr Navalny’s name-recognition has grown from 6% to 37%, even though the share of people ready to vote for him has fallen. Yet critics say he has failed to convert this into a political structure or campaign. “He held the pause for too long,” says Gleb Pavlovsky, a former Kremlin adviser. This has given the Kremlin breathing space in which to intimidate Mr Navalny’s donors and arrest some protesters, dampening the mood for action.

Jailing Mr Navalny might play to his advantage, further eroding the Kremlin’s legitimacy. Boris Akunin, a writer and opposition figure, says, “if Navalny gets imprisoned, Russia will get onto a track that will take it to the last station: Revolution Square.” His conviction may be predictable, but its consequences are not.