Ukraine's President Viktor Yushchenko has formally nominated Yulia Tymoshenko, the leader of a pro-Western coalition, as prime minister.
Ms Tymoshenko's nomination was put forward by the Ukraine parliament's speaker earlier today.
Ms Tymoshenko, a former prime minister, needs to have the backing of at least 226 of parliament's 450 members to be confirmed.
Her bloc and the pro-presidential Our Ukraine party have a majority of just two in the 450-seat assembly. Both parties are linked to the 2004 Orange revolution that bought Yushchenko to power.
Yulia Tymoshenko stood by Mr Yushchenko's side during those street protests and was appointed prime minister in 2005. However she was sacked eight months later and the two reconciled only at the beginning of this year.
There has been speculation that some Our Ukraine members object to Ms Tymoshenko's return to power and could splinter off to join the Regions party of outgoing Prime Minister Viktor Yanukovich.
Earlier, speaker of the parliament Arseniy Yatsenyuk presented Ms Tymoshenko as prime minister to the president during the first session he chaired.
Ms Tymoshenko is seen as likely to make a bid for the presidency when elections are held either in 2010 or 2011.
