By Mariya Gordeyeva
AKTAU, Kazakhstan (Reuters) - An outspoken critic of Kazakh President Nursultan Nazarbayev was accused on Thursday of colluding with a billionaire fugitive to overthrow the government in a trial the United States says will test democratic reforms in the oil-rich former Soviet state.
Prosecutors accused Vladimir Kozlov, leader of the unofficial political party Alga!, of helping orchestrate dissent among striking oil workers in the prelude to deadly rioting on December 16-17 that shattered Kazakhstan's reputation for stability.
He denied the charges and, as the trial began in a packed courtroom, around 30 of his supporters shouted for his release.
At least 15 people were killed in western Kazakhstan when police opened fire on protesters in riots that followed months of protests by sacked oilmen, posing the most serious challenge to Nazarbayev in his more than two decades as president.
Kazakhstan's leaders are particularly wary of dissent following mass protests in Russia, which shares a language favored by millions of its citizens and remains the country's biggest trading partner.
In recent years, they have tried to balance their desire to preserve stability and robust economic growth with efforts to improve the country's image on the world stage.
Kozlov, 52, faces a maximum prison term of 13 years if convicted of charges that include inciting social discord and trying forcibly to overthrow the constitutional order. Two independent opposition activists are on trial alongside him.
One of the accused, 54-year-old local oil worker Akzhanat Aminov, pleaded guilty. The other activist, Serik Sapargaly, 60, said he accepted some blame without admitting full guilt.
Dressed in an open-necked shirt, Kozlov, who denied all charges, waved at supporters when led into a glass box in the court in the Caspian port city of Aktau, 2,600 km (1,625 miles) west of the capital, Astana.
Prosecutors said he had acted under orders from Mukhtar Ablyazov, the self-exiled former head of Kazakh bank BTA and an arch foe of Nazarbayev, to travel the country and find "a weak spot".
Kozlov had earlier asked the judge to postpone the hearing to allow him more time to familiarize himself with the 1,300-page case document. Permission was denied, prompting slow claps from his supporters that drew a warning from the judge.
"He will fight the charges," Kozlov's wife, Aliya Turuzbekova, told Reuters after the court adjourned for the day. "But he understands that a conviction and severe punishment await. He is preparing his family for this."
Britain granted political asylum to Ablyazov last year as he awaited embezzlement charges brought by his former bank, which he has said are politically motivated. But his whereabouts are unknown since he fled after being convicted in February of contempt of court.
Back home, Kazakhstan's marginalized and fragmented opposition enjoys relatively little popular support. Several hundred people attended rallies held monthly in Almaty, the country's largest city, after a January 15 parliamentary election.
Nazarbayev, a former steel worker who rose through the ranks of the Soviet Communist party, remains popular across the mainly Muslim country of 16.7 million people and is credited for sustained economic growth in an otherwise volatile region.
Robert Blake, U.S. assistant secretary of state for South and Central Asia, said Kazakhstan had a "particular responsibility" to demonstrate reforms it pledged as chair of the Organisation for Security and Cooperation in Europe in 2010.
"We hope that (the trial) is going to be conducted in a fair, impartial and open way," Blake told reporters in Almaty.
"We also hope that the trial itself will not undermine some of the progress that Kazakhstan is making to develop a multi-party democracy," he said on the eve of the trial.
January's election allowed three parties into Kazakhstan's parliament for the first time in 20 years of independence, a small concession to democracy in the face of growing frustration over the unequal distribution of the country's mineral wealth.
But the second- and third-placed parties are broadly sympathetic to Nazarbayev's ruling Nur Otan party, which itself won 81 percent of the vote. The OSCE's observer mission said genuine opposition parties had been barred and media shackled.
Kozlov's Alga! party, long denied official registration, was not eligible to run. He was arrested a week after the election in an apparent crackdown on vocal critics of the government.
"Anything short of a scrupulously fair trial will only serve to cast further doubt that the case against these men is arbitrary and politically motivated," Mihra Rittmann, Central Asia researcher for Human Rights Watch, said in a statement.
Prominent rights activist Yevgeny Zhovtis, observing the trial, said he expected a verdict by the end of August. Earlier trials of those accused of participating in the violence saw 23 people jailed, including six policemen.
(Additional reporting and writing by Robin Paxton in Almaty; Editing by Andrew Osborn)