KHARKIV, Ukraine: A Ukrainian court on Tuesday delayed the new trial of jailed opposition leader Yulia Tymoshenko on embezzlement and tax evasion charges by another month because of her chronic back problems.

A judge in the eastern city of Kharkiv, where the former prime minister is already serving a seven-year sentence she received last October on charges of abuse of power, set the next hearing for September 11.

Tymoshenko claims that both cases are part of a political vendetta against her by President Viktor Yanukovych following his narrow victory over her in 2010 polls.

The treatment of Tymoshenko, a co-leader of the 2004 pro-democracy Orange Revolution, has sparked concern in the West and prompted the European Union to tell Kiev that signing a deal on possible future membership for Ukraine would be conditional on Tymoshenko's release.

The European Court of Human Rights has also provisionally scheduled an August 28 hearing to examine whether Tymoshenko's initial arrest and subsequent treatment during her first trial were legal.

The new case relates to Tymoshenko's time in the 1990s as head of Ukraine's largest gas trading company. Previous government probes into her leadership role there had been dropped and the case dismissed.

A second conviction could keep Tymoshenko in prison even if she successfully appealed the first case, or extend her current jail term.