Clare Nuttall in Almaty -

Kazakh opposition leader Vladimir Kozlov was sentenced to seven and a half years in prison on October 8 in connection with December's clashes in Zhanaozen. As one of the strongest critics of President Nursultan Nazarbayev's regime, the sentence is a severe blow for Kazakhstan's already weakened opposition.

Kozlov, the leader of the unregistered Alga! DVK party, was found guilty of three charges by a court in Aktau, the administrative centre of the western Mangistau region. He was found guilty of leading a criminal organisation (alongside fugitive banker Mukhtar Ablyazov), inciting social hatred, and attempting to overthrow the government. The sentence is slightly shorter than the nine years requested by the prosecutor.

Opposition activist Serik Sapargali and trade unionist Akzhanat Aminov were tried alongside Kozlov but received suspended sentences. Kozlov denied all charges, which he called an attempt to destroy the opposition in Kazakhstan.

Speaking to bne in Almaty on October 5, the deputy leader of Alga's coordination committee, Mikheil Sizov, said: "Unfortunately the court system in Kazakhstan is not fair... The decision has been made in the administration of the president. It's completely political."

However, Sizov insisted that despite the jailings, the party will continue to work for a more democratic system in Kazakhstan. "Vladimir Kozlov build up our organisation, but it is not like a presidential system; we can continue without him. He is a bright and strong leader, and will be a big loss, but we will continue our work."

All three charges against Kozlov were connected to his support for striking oilworkers in Zhanaozen, an oil town around 150km from Aktau, where workers at the Uzen field started a seven month strike in May 2011. On December 16, 2011, Kazakhstan's independence day, fighting broke out between demonstrators and police who were trying to clear the central square so a concert could go ahead. Mass riots erupted and at least 14 people were shot dead by security forces. Another man was killed in nearby Shetpe the following day when residents rioted in solidarity.

Kozlov and his colleagues were accused of inciting social unrest in Zhanaozen and distributing leaflets to workers calling on them to resist the authorities. The opposition leader was arrested on January 23, as he returned from Brussels where he had addressed the European Parliament on the events in Zhanaozen. He was among several Alga members, opposition activists and independent journalists detained as part of a clampdown by security forces on opposition activity.

Kozlov's Alga party is one of the most outspoken critics of President Nursultan Nazarbayev's government, in a country where there are few dissenting voices. Nazarbayev, who has ruled since Kazakhstan became independent in 1991, has a high level of popularity thanks to the country's steady economic growth and social and political stability. However, the latter has come under threat since the Zhanaozen tragedy, and a series of bombings, attributed to terrorists, in the west of the country.

The authorities maintain a tight grip on the country's power structures, and no election has ever been recognised as free and fair by international observers. The April 2011 presidential elections, which Nazarbayev won with 95% of the vote, was criticised by the OSCE for serious shortcomings including ballot box stuffing and other irregularities. Alga has been unable to take part in recent elections as it has been denied registration, instead leading a campaign calling on voters to boycott the polls.