KIEV: Ukraine’s Parliament on Wednesday delayed a key vote on the release of jailed former Premier Yulia Tymoshenko, a move that threatens to derail this ex-Soviet republic’s push toward the European Union and shift it back into Russia’s orbit.

Parliament Speaker Volodymyr Rybak closed the session, attended by two top EU envoys, saying the bill allowing Tymoshenko to travel to Germany for medical treatment was not yet ready and could not be brought to a vote. He said they will take up the bill again on Tuesday, when parliament meets next.

EU officials have warned that they will not sign a free-trade and political association agreement with Ukraine at the end of the month if Tymoshenko remains in jail. They have urged her rival, President Viktor Yanukovych, to release her for treatment in Germany as a compromise measure. Previously they have called Tymoshenko’s trial politically motivated.

Opposition leaders accused Yanukovych and his allies in parliament of purposely sabotaging the long-awaited EU deal. Russia staunchly opposes the signing of the EU agreement and has used threats, sanctions and offers of price discounts in an attempt to lure Kiev away from the EU and into a Moscow-led customs union instead.

After the session was closed, parliament erupted with angry chants of “Shame! Shame!” from opposition lawmakers, some dressed in white sweaters that read “Freedom to Ukraine” and others wearing red sweaters reading “Ukraine is Europe.”

“You are ready only for political persecution, blackmail, pressure and to hold on to your power,” opposition leader and top Tymoshenko ally Arseniy Yatsenyuk told parliament, referring to Yanukovych. “We, however, want the power to belong to the people of Ukraine.”