The breakdown weakened hopes for an agreement before the new parliament's first session next week.
The announcement came after seven weeks of negotiations to put together a new government appeared to be making progress, with former Prime Minister Yulia Tymoshenko and the Socialists suggesting an agreement with Yushchenko's Our Ukraine could even be signed this week, the AP reports.
A revived Orange coalition would reunite the three parties that drew hundreds of thousands of people to the streets in 2004 to protest a rigged presidential election, helping prompt a new vote that Yushchenko won.
Yushchenko and Tymoshenko later had a major falling out, and the partnership between their parties disintegrated into mutual accusations. After March 26 parliamentary elections, however, all three parties said they were committed to trying again to keep Ukraine on its reformist, pro-Western path.
But a senior Our Ukraine official Roman Zvarych on Tuesday accused Tymoshenko and Socialist Party leader Oleksandr Moroz of issuing ultimatums over jobs in the new government. Tymoshenko, whose party won more votes than the other potential coalition partners, has demanded to be prime minister again.
The Socialist Party has supported her in exchange for her blessing for its leader, Oleksandr Moroz, to get the powerful parliamentary speaker job.
Pressure is building on the parties to reach an agreement because parliament is scheduled to hold its first session on May 25. Lawmakers have one month after the first session to form a coalition, and another month to name the government. But Ukrainian politics has been effectively frozen for much of this year due to campaigning and then the coalition talks, leading to calls for the lawmakers to sort themselves out quickly.
The main stumbling block still appears to be the prime minister's job, with many in Yushchenko's circle extremely reluctant to see Tymoshenko return.
After it turned out that Deputy Prime Minister Andrei Belousov included the Fonbet betting company in the list of backbone enterprises that can count on state support, everyone started talking about these bookmakers.