Ukraine's ruling coalition took another hit on February 18 as the third-largest parliamentary faction, the pro-Western Samopomich Party of Lviv mayor Andriy Sadovyi, pulled out on the heels of ex-prime minister Yulia Tymoshenko's faction, with both citing backroom power-broking by the nation's leaders and oligarchs as the reason.

The departures will deepen the Kyiv government's isolation and unpopularity and threaten to hasten its collapse after some ugly public feuding and a spate of resignations. Most recently, the reformist Economy Minister Aivaras Abromavicius quit his post, claiming that top-level corruption and abuse of office is destroying efforts to get war-torn Ukraine on its feet again.

"The leaders of the Samopomich party have recognised as impossible a further alliance of its [parliamentary] faction with political forces involved in an oligarchic coup in parliament, and are halting its membership in the coalition," said a statement by Sadovyi's party, the exit of which effectively eliminates the coalition's parliamentary majority..

A day earlier, former premier Tymoshenko also said the withdrawal of her Batkivshchyna (Fatherland) party was due to the grip of a "shadow clan-political coalition" on Ukraine's politics. "The faction considers it unacceptable to stay in this flock, which actually has no chance, because it doesn't want to carry out reforms, to defend Ukraine, restart our lives," Tymoshenko said.

The political demarches were triggered by a failed vote of no confidence in Prime Minister Arseny Yatsenyuk and his cabinet on February 16, when only 194 lawmakers backed the motion instead of the minimum 226 votes needed to oust the head of government.

Pro-Western lawmakers accused Yatsenyuk, President Petro Poroshenko and Ukraine's oligarchs of reaching backroom agreements to leave the premier in office, using their supporters in parliament to kill the motion to unseat him. Poroshenko appears to have reluctantly kept Yatsenyuk while pledging to refresh the cabinet with "technocrats" to satisfy the demands of the International Monetary Fund (IMF) and Ukraine's other donors.

The events were "a frank conspiracy between the senior leadership of the state, on the one hand, and oligarchs and oligarch-controlled parliamentary forces on the other", a Samopomich (Self-Reliance) statement said. "This was a final attempt to cement the power of the oligarchy and kleptocracy in Ukraine."

"No right to allow Ukraine's break-up"

Yatsenyuk inferred that Samopomich had lost its nerve as Ukraine's political crisis deepens: "I can only feel for them. It's necessary to be able to bear political responsibility together," he said during a cabinet meeting after Sadovyi's party pulled out, Ukrainska Pravda online newspaper reported.

Meanwhile, the prime minister has been looking to shore up the coalition with overtures to smaller factions, with Ukraine's Radical Party saying the same day that it is ready to rejoin the alliance after leaving last year.

Yatsenyuk also called upon Poroshenko, his eponymous bloc in parliament, and other democratic forces to prevent the worst case scenario. "I am addressing the president, his faction, and all reasonable and democratic forces: let's turn a new page. We have no right to allow the horrible scenario of the country's break-up," he said.

He added stressed that Ukraine's political forces "have no right to repeat the mistakes" of 2005, when after the Orange Revolution the pro-Western President Viktor Yushchenko found himself locked into a long drawn-out infighting with Tymoshenko.

Earlier in the week, Poroshenko called upon his own bloc, Yatsenyuk's People's Front, Batkivshchyna and Samopomich to join in an overhaul of the cabinet in order to avoid a deeper political crisis that may require snap elections to parliament.

If the coalition fails to agree on a new cabinet and fragments, this can send Ukraine back to a four-month populist election campaign with unpredictable results, which the country will not be able to afford either politically or financially.