Parliament's support was needed to amend the 2014 budget to take account of falling revenue and release an additional 9.1 billion hryvnia ($758 million) to finance the military.

Yatseniuk had said the government would have defaulted on debt payments and missed out on the release of further funds under a $17-billion International Monetary Fund bailout if it had failed to pass the legislation.

"The laws the government is insisting on are unpopular and difficult, but very necessary," Poroshenko said, adding that they would "enable the economy, the state as a whole, to function.”

Laws passed on Thursday also introduce an additional 1.5-percent personal income tax until the end of the year to cover the military. Taxes were raised on tobacco and the mining, oil and gas sectors. Nearly 2 billion hryvnias were earmarked for rebuilding of infrastructure damaged by fighting in the east.

The exit of two parties from the ruling coalition last week amounted to the start of a campaign for seats in a legislature still packed with former allies of pro-Russian president Viktor Yanukovych, who was ousted by street protests in February.

Western governments have come to regard Yatseniuk as a key interlocutor in the worst standoff between Russia and the West since the Cold War ended. His departure would have been seen as leaving a vacuum at the heart of decision making.

The United States and European Union imposed sanctions on Moscow this week that were far tougher than earlier measures. Russia has been hitting back.

It announced a ban on fruit and vegetable imports from Poland on Wednesday and a day later placed an embargo on Ukrainian fruit juice. Greek fruit and U.S. poultry could follow, Russian media said. (rt/ez)