You're reading: Jailed Tymoshenko accused of treason in Ukraine (updated)

Ukrainian authorities stepped up their legal assault on jailed former Prime Minister Yulia Tymoshenko on Tuesday when parliament accused her of committing high treason during natural gas import negotiations with Russia in 2009.

Tymoshenko, 51, the country’s top opposition leader, is serving a seven-year prison sentence after being convicted of abusing her powers during those gas negotiations. The verdict was condemned as politically motivated by the United States and the European Union and has seriously strained Ukraine’s ties with the West.

Ukraine’s parliament, which is controlled by President Viktor Yanukovych, voted on Tuesday to support the findings of a legislative investigation that claims Tymoshenko’s actions "bear signs of high treason" in favor of Russia and to give those materials to prosecutors and the security service.

The contract, negotiated by Tymoshenko at the height of a bruising pricing war with Moscow, significantly increased the price Ukraine pays for Russian gas imports.

Parliament charged on Tuesday that Tymoshenko agreed to the price increase because a company she once headed owed Russia more than $400 million and she faced criminal prosecution on corruption charges there.

"These circumstances, without a doubt, testify to a conflict of interests and significantly influenced the decision of the prime minister of Ukraine in favor of a foreign state," parliament said in a statement.

Tymoshenko’s office dismissed the accusations as "complete rubbish."

"The authorities’ attempts to get rid of the main political opponent know no limits," said Tymoshenko spokeswoman Natasha Lysova.

Tymoshenko’s lawyer, Serhiy Vlasenko, has acknowledged that a company Tymoshenko headed in the mid-1990s, Unified Energy Systems, did have a $400 million debt to Russia, but insisted that Tymoshenko has not managed or owned stock at that company for more than 10 years and was not responsible for the debt. Vlasenko also said that criminal charges against Tymoshenko of bribing Russian Defense Ministry officials have long been dropped.

Tymoshenko says that agreeing to Russian terms during the negotiations was the only way to stop a gas war that had caused supply disruptions in Ukraine and across Europe after Russia cut gas flows to Ukraine and European consumers. She accused Yanukovych, her longtime foe, of putting her in prison to bar her from parliamentary elections this fall. Tymoshenko narrowly lost the presidential race to Yanukovych in 2010.

Besides the gas case, she also faces a slew of other corruption and fraud charges.

Tymoshenko has complained of experiencing severe back pain in custody, but said prison doctors are denying her treatment at a specialized medical clinic as recommended by a group of German doctors who examined her and by the European Court of Human Rights. Prison authorities reiterated Tuesday that they intend to treat Tymoshenko in custody.