Russian tycoon Mikhail Prokhorov has resigned as leader of a pro-business party and says he will not run for the State Duma in parliamentary elections this December.

The 46-year-old billionaire resigned Thursday, ending his three-month stint at the helm of the Right Cause party. Earlier, the party voted to depose him in the wake of infighting among senior members.

Prokhorov is one of Russia's richest men and the owner of a U.S. professional basketball team. He says he refuses to tolerate interference from the Kremlin and has called on his supporters to leave what he called this “puppet party.”

Right Cause was expected to draw on the support of opposition-minded and pro-business voters in elections to Russia's national parliament on December 4. The Associated Press says the party is viewed as a Kremlin creation designed to attract opposition-minded voters, while creating an illusion of competition with the ruling party.

But Prokhorov has vowed not to leave politics. He says he plans to establish his own political movement and that he is not afraid of being imprisoned like fellow tycoon Mikhail Khordorkovsky, who supporters say was jailed for challenging the Kremlin.

At the time of his arrest, Khodorkovsky was supporting politicians opposed to then-President Vladimir Putin. Khodorkovsky, once Russia's richest man, remains in prison after being convicted of tax fraud, money laundering and stealing from his former oil company, Yukos.

Prokhorov has a fortune estimated by Forbes magazine at $18 billion. He heads the Onexim Group, an investment firm that has interests in mining, banking and other industries.