Today, lawmakers had been due to vote on returning Yuliya Tymoshenko to the post of prime minister.
They also wanted to vote on giving an ally of President Viktor Yushchenko the post of parliamentary speaker.
Lawmakers from the Party of Regions took over the podium and disconnected the electronic voting system.
The Party of Regions objects to the nominations and is against combining the two votes in a single ballot. It also complains it has been shut out of key parliamentary committees. It successfully blocked a session of the legislature on June 27.
The pro-Russian Party of Regions has vowed to continue blocking parliament until the new governing coalition uniting the three parties behind the 2004 Orange Revolution agrees to its demands.
(compiled from agency reports)
MORE: For coverage of the ongoing dispute in Ukraine's legislature from RFE/RL's Ukrainian Service in Ukrainian, click here.
BEHIND THE IMAGES: Click on the links below to read RFE/RL's profiles of some of the key players in Ukraine's March 26 legislative elections:
Click on the image to view a photo gallery of some of the key players in the Ukrainian elections.