Ukraine's parliament has delayed a vote on a bill that would allow jailed former prime minister Yulia Tymoshenko to go to Germany for medical treatment.
Ms. Tymoshenko's supporters in parliament left their seats in anger Wednesday after the vote was delayed.
The opposition leader is serving a seven-year prison term on charges of abuse of office, after a trial the European Union has called politically motivated. She has been a fierce rival of current President Vyktor Yanukovich.
She was jailed in 2011 and later transferred to a hospital unit for treatment of chronic back pain. Her continued detention is an obstacle to a key association deal between Ukraine and the 28-nation EU that was to be signed at a summit in Vilnius later this month (November 28-29).
Moscow has pressured Ukraine not to sign the deal that would turn the former Soviet republic toward the West and away from Russia.