Yulia Tymoshenko was not approved as the prime minister, her supporters immediately said that the votes were technically flawed.
Tymoshenko was nominated by President Viktor Yushchenko, but received only 225 votes in each of two rounds of voting in the Verkhovna Rada, one vote short of the absolute majority needed. However, her supporters alleged that the machine tabulating the votes had been tampered with.
"It's not the lawmakers that malfunctioned, it's the machine. It was programmed for 225 votes," said Volodymyr Silenko, a parliament member from Tymoshenko's party.
The dispute over the vote count adds a new exacerbating element to Ukraine's chronically chaotic politics.
After the second disputed vote, the parliament went into recess and members of the anti-Tymoshenko Party of Regions, which has the largest contingent in parliament, blockaded the parliament's rostrum in an attempt to prevent the session from reconvening.
Although the pro-Russian Party of Regions, led by the previous prime minister Viktor Yanukovych, has the largest number of seats, the parties of Yushchenko and Tymoshenko together obtained a narrow majority of the seats in September's national elections.
Tymoshenko and the president have often locked horns in the past - he dismissed her as prime minister in 2005 after she had served only seven months - but agreed to form a majority coalition on the understanding that she would be nominated to return to the premier's post.
Tymoshenko is one of the most polarizing figures in Ukrainian politics. Her backers have intense loyalty to her, especially after the 2004 Orange Revolution protests in which she was the driving figure. Others either despise her or are uncomfortable with her fiery oratory and intense personal ambition.