Ukraine's newly created pro-Russian governing coalition on Tuesday proposed a bitter rival of President Viktor Yushchenko as the next prime minister, an appointment that would mark a humiliating defeat for the president.

The parliament speaker signed the coalition's nomination of Viktor Yanukovych as premier and forwarded it to Yushchenko's office. The president has 15 days to consider the request before forwarding it back to parliament for a vote. He has no right to veto the choice.

CountryWatch: Ukraine

The nomination came hours after the new parliamentary coalition, which brings together eastern Ukrainian industrialists of the Party of Regions, the Communists and the Socialists, was formally announced in parliament, striking a major blow to the pro-Western reformers who helped bring Yushchenko to power in 2004.

It was Yanukovych's fraud-marred presidential victory that sparked the mass protests that became known as the Orange Revolution. His victory was later annulled, consigning him to the political wilderness and severely embarrassing the Kremlin, which had openly backed his candidacy. But Yanukovych rebounded in the March 26 parliamentary election, with his party winning more votes than any other.

A government led by Yanukovych would present a major obstacle to Yushchenko's efforts to steer the country toward reform and closer ties with Western Europe. Under such a government, Ukraine would also likely slip back under the influence of Moscow.

The new coalition was created after Socialist Party leader Oleksandr Moroz, the new parliament speaker, abandoned his former Orange Revolution allies to form the new union, which he said was the only way to unite the country.

Ukraine has been suffering political paralysis since the March election ended without giving any party the majority, leaving the nation deeply split over whether to seek closer ties with Moscow or the West.

Moroz formally announced the coalition in the chaotic session hall Tuesday to applause from the coalition members — and shouts of "Judas!" from his former allies.

The alliance controls at least 233 seats in the 450-member parliament.

Before announcing the new coalition, lawmakers scuffled, and one legislator from the president's party appeared to suffer a broken nose. Moroz had to be flanked by Party of Regions deputies for protection. Lawmakers from the bloc of Yulia Tymoshenko, a former prime minister and popular figure in the Orange Revolution, used sirens to drown out parliamentary speeches. Moroz called a four-hour recess.

Yushchenko's allies pleaded with the president to use his new constitutional powers to dissolve parliament and call a new election, arguing that the new coalition is illegitimate. Under rules agreed to by the Orange coalition members, if any party left, the other members should have been given 10 days to hunt for new partners, lawmakers said.

Yanukovych said his party didn't support new elections, but also didn't fear them.

"If it happens, we will get a total victory and could stop this mess," he said.