Parties linked with Ukraine's "Orange Revolution" formed a wafer-thin majority coalition in parliament on Thursday, with former prime minister Yulia Tymoshenko due to get her job back once a government is formed.
The coalition, with only a single vote to spare, was created after weeks of tense negotiations between two parties associated with the mass 2004 protests that swept pro-Western President Viktor Yushchenko to power.
Further talks are needed to elect a speaker and piece together a cabinet. Analysts immediately raised questions about the viability and effectiveness of such an administration after three years of turmoil in the ex-Soviet state.
Tymoshenko, abandoning her trademark peasant braid, said nothing in the chamber after the announcement and was reserved later when addressing reporters. "We have no euphoric illusions about how difficult it will be for this democratic coalition to work. We know some political forces will work for its destruction," Tymoshenko said.
"But we believe that from today our coalition will start to grow stronger ... We can form an effective government and provide hope for the country's deep, systematic transformation." Her aim was to uproot corruption once and for all, she said, vowing to "create a team made up not of thieves or corrupt and criminal businessman, but professionals".
Roman Zvarych, an ally of President Viktor Yushchenko who was chairing the session, said 227 signatures appeared on the document - one less than expected. A total of 226 votes is needed to win most motions in the chamber.
He immediately closed the session until Tuesday, a day after coalition deputies meet to nominate Tymoshenko as prime minister. Parliament now has 30 days to form a government.
The coalition's two groups, Yushchenko's Our Ukraine party and Tymoshenko's bloc, set aside differences in the election. Agreement must still be reached on a figure for the powerful position of speaker. Our Ukraine put forward Arseniy Yatsenyuk, foreign minister, seen as acceptable to all political forces.
Analysts said a coalition with the narrowest of majorities and with uneasy participants had to prove its durability. "This was quite a difficult birth which, by all appearances, may not yet be over," said Viktor Nebozhenko of the Barometer think tank. "This coalition has so far done nothing active so we can say nothing about whether it can be viable or effective."
Both "orange" groups had given initial approval to a post-election coalition, but key presidential allies criticised parts of the accord and withheld approval. All but one were persuaded to sign on Wednesday after talks with Yushchenko.
After coming to power on the back of mass protests against electoral fraud in 2004, Yushchenko pledged to move Ukraine closer to the West and join the European Union and Nato.
But the movement could not maintain its unity and the president sacked Tymoshenko as prime minister months later. The two leaders were reconciled during the September campaign. Tymoshenko was accused during her first term of frightening investors with calls to review privatisations. She had a chance to become prime minister again after an election last year, but "orange" defections sank a prospective coalition.