The proposal to oust the Supreme Rada speaker came Friday from pro-presidential faction Our Ukraine after Moroz signed a controversial law on Cabinet appointments that substantially cut the president's powers. The law came into force despite being vetoed twice by the president.
"We will be politically delighted to vote for Moroz's removal from the post of speaker," said Tymoshenko, a key figure in the 2004 'orange revolution' which brought to power Western-leaning President Viktor Yushchenko.
Moroz heads the Socialist Party, which abandoned a Tymoshenko-led alliance of orange forces to facilitate the creation of a pro-Russian coalition last July, led by Viktor Yanukovych, who became prime minister a fortnight later.
Yanukovych has been steadily consolidating his power in the ongoing struggle between pro-presidential and pro-premier factions over the past six months.
Under Ukrainian law, the parliamentary speaker can sign a bill into law, if approved by two-thirds of votes in parliament, if the president fails to do so within a month.
The prime minister first vetoed the bill on January 12, but the Supreme Rada overrode him with 366 votes when a former opposition bloc joined the parliamentary majority supporting Prime Minister Yanukovych. Parliament also rejected all presidential amendments to the bill.
On January 18, Yushchenko again refused to sign the law, saying the Supreme Rada had made new changes to the document.
Yushchenko repeatedly said the provisions allowing factions to nominate the prime minister, and defense and foreign ministers, as well granting them the authority to dismiss ministers, ran counter to the national unity pact political leaders signed in August in a bid to end a protracted political crisis in the ex-Soviet state following the March parliamentary elections.
The president pledged to appeal to the Constitutional Court against the law.
The Supreme Rada has sacked several president-appointed ministers, including Foreign Minister Borys Tarasyuk, the president's key ally who had actively promoted pro-Western policies.
