The Ukrainian parliament declared President Viktor Yanukovich constitutionally unable to carry out his duties on Saturday and set an early election for May 25.
Deputies in the assembly stood, applauded and sang the national anthem.
A spokeswoman for Yulia Tymoshenko says the former Ukrainian prime minister and opposition icon has been released from prison.
Natasha Lysova told The Associated Press that Tymoshenko was released from her prison in Kharkiv on Saturday. She did not have further details.
Tymoshenko is the arch-rival of President Viktor Yanukovych and her arrest in 2011 and conviction on charges of abuse of office were widely seen as a case of political revenge.
The claim of her release comes one day after the Ukrainian parliament voted to decriminalise the charge on which she was convicted.