By Richard Balmforth
KIEV (Reuters) - Former Ukrainian Prime Minister Yulia Tymoshenko appeared in court for a pre-trial hearing over charges of abuse on power Friday as thousands of people massed in support of her in the capital's city center.
Tymoshenko, 50, a fierce critic of President Viktor Yanukovich, put on a typically defiant performance. She denounced the hearing as an arranged "farce" and told the judge to his face that he was a presidential "puppet."
"At such an important moment for Ukraine, I do not want in that chair such a judge as you. I am throwing down this challenge to you because I consider you a puppet of the presidential administration," she told judge Rodion Kyreyev in court.
Outside the court earlier she told reporters: "This mock trial was organized and served up by Viktor Yanukovich. Nobody has any doubts that the courts and the state prosecution are in private hands and there will be no justice."
The hearing was to decide whether to send Tymoshenko for trial on a charge of abuse of power in connection with a gas supply agreement with Russia in January 2009 when she was prime minister.
That agreement ended a stand-off between Russia and its ex-Soviet neighbor over the pricing of Russian gas which had led to supplies being cut off to Western Europe. It has since been denounced by the Yanukovich leadership as a sell-out, though Kiev is continuing to observe it.
Tymoshenko became known as the "gas princess" in the late 1990s as owner of a company which bought and sold Russian gas.
Since losing to Yanukovich in a fight for the presidency in February 2010, she has failed to unify the opposition around her.
But, with her trademark peasant-style hairbraid and a combative manner, she still remains popular across Ukraine and Friday she brought thousands out onto Kiev's central thoroughfare.
Supporters carried slogans that read: "We will defend Ukraine ! Down with puppet courts! We are for Yulia, for Ukraine!.
Tetyana Borik, 47, a supporter who had come from Poltava, 350 km (220 miles) east of Kiev, said: "I believe that the case against Tymoshenko is political. It is not her who is guilty but (former president Viktor) Yushchenko."
Tymoshenko came to power, serving as prime minister for two terms, following street disturbances called the Orange Revolution in 2004 which doomed Yanukovich's first attempt to secure the presidency.
Yushchenko subsequently became president with Tymoshenko as prime minister but the two repeatedly fell out over style and policy.
"I am ashamed to live in this country. I want justice. I want to express support for a leader of whom those in power are afraid," said Igor Zakharenko, 50, another Tymoshenko supporter.
(Reporting by Yuri Kulikov and Pavel Polityuk; Writing by Richard Balmforth; Editing by Angus MacSwan)