(Reuters) - A man long relied on by President Vladimir Putin to rule one of Russia's most violent cities was sentenced to 10 years in jail on Wednesday on charges of plotting a "terrorist" attack to kill a political rival.

A military court convicted accused Said Amirov, the mayor of Dagestan's capital Makhachkala from 1988 to 2013, of conspiring to use an anti-aircraft missile to shoot down a plane carrying the local head of the state pension fund.

His nephew Yusup Dzhaparov, former deputy mayor of a nearby city, was sentenced as a co-conspirator to eight and half years in jail, Russian state television Vesti-24 reported.

The two men have dismissed the charges as absurd and fabricated. Their lawyer said he would appeal what he called a politically motivated ruling.

"Political issues need to be decided at the political level and not by investigators and law enforcement," the defense lawyer said, cited by the Itar-Tass news agency.

Amirov's arrest in June 2013 was seen as Putin's attempt to assert control over a region dogged by mafia-style crime and Islamist insurgency ahead of his 2014 hosting of the winter Olympics on the other side of the mountains.

Until then, he seemed untouchable, protected by the Kremlin as the local boss of the president's United Russia party.

In the restive North Caucasus region, Putin's policy to impose control has been to rely on strongmen like Amirov, who run business empires and wield personal authority over police.

The court in the southern city of Rostov ordered Amirov, who was left wheelchair-bound after one of over a dozen attempts to assassinate him, to be held in a maximum security prison and be stripped of his state awards, Itar-Tass reported.

Dagestan, where Boston Marathon bombing suspect Tamerlan Tsarnaev spent the first half of 2012, is the main focus of an insurgency by fighters who want to found an Islamic state in Russia's Caucasus mountains.

Amirov was so powerful that investigators have said they spent two years preparing for his arrest and sent special forces from Moscow with helicopters and armored personnel carriers to do so.

(Reporting by Alissa de Carbonnel; Editing by Tom Heneghan)