Ukrainian Economy Minister Aivaras Abromavicius quit Wednesday saying his ministry was being hijacked by corrupt vested interests, dealing another blow to Western hopes that the country can reform itself.

In his resignation statement, Abromavicius singled out a close ally of billionaire President Petro Poroshenko, accusing him of blocking his ministry's work and trying to control its revenue streams. Abromavicius's exit could derail plans to privatise around 100 state owned companies, which were a plank of a reform program to turn around an economy which shrunk by more than a tenth last year.

There has been mounting public anger that the new, pro-Western government that came to power after a pro-Russian president was toppled by protests in 2014 has not delivered on promises to stamp out corruption. The government's approval ratings have fallen sharply. Ukraine's international backers, including the United States and the European Union, have also become increasingly impatient with the slow pace of change in a country into which they have pumped billions of dollars in aid.

Any threat of Prime Minister Arseny Yatsenyuk's government collapsing would also deeply worry Ukraine's Western partners, who have backed the coalition to keep the country from falling back into Moscow's orbit.