Ukrainian Economy Minister Aivaras Abromavicius quit on 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 President Petro Poroshenko, accusing him of blocking his ministry's work and trying to control its revenue streams.

Abromavicius' exit could derail plans to privatize around 100 state owned companies, which were a plank of a ­reform program to turn around an economy shrunk by over one-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 US and the EU, 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 the 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.

"My team and I have no wish to be a cover for open corruption or puppets under the control of those who want to establish control over state money in the style of the old authorities," Abromavicius said.

"I can't be effective ­under such a system. It is impossible for technocrats to work with guys that want to usurp power, and make processes un-transparent."

Ukraine has struggled economically since 2014, which was followed by Russia's absorption of Crimea and by war in the east of the country against the rebels Kiev says are supported by Moscow.