Ukraine's parliament bowed Thursday to pressure from its Western lenders and delayed voting on legislation giving it the power to remove heads of the country's nascent anti-corruption agency.

The National Anti-Corruption Bureau of Ukraine (NABU) has come under political pressure since launching a series of investigations against top officials in the past year.

A bill submitted jointly by President Petro Poroshenko's ruling party and its coalition partner granting parliament the right to remove corruption investigators appeared to be the last straw for the IMF and World Bank.

IMF chief Christine Lagarde said on Wednesday the global lender was "deeply concerned by recent events in Ukraine that could roll back progress that has been made in setting up independent institutions to tackle high-level corruption".

She said the work of NABU and the Special Anti-Corruption Prosecutor's Office (SAPO) -- a partner agency that is also under attack -- was "crucial to achieving stronger and equitable growth".

The World Bank echoed Lagarde's unusually blunt remarks in a statement issued on Facebook on Thursday.

"We are deeply concerned about recent attacks on independent anti-corruption institutions such as NABU and SAPO in Ukraine that threaten their ability to fight corruption and recover stolen assets," it said.

Poroshenko's party appeared to be responding to the statements by announcing that the disputed legislation would not be examined on Thursday as some lawmakers had sought.

NABU has targeted the son of the powerful interior minister as well as senior defence officials and even the mayor of the strategic Black Sea port city of Odessa.

But it has faced resistance from ministries and tycoons whom critics accuse of robbing the strife-torn state.

Bill co-author Artur Gerasymov said his "colleagues need two weeks to develop alternative draft legislation".

The course being charted by Ukraine since its 2014 pro-EU revolution regained international attention this week when security services attempted to arrest former Georgian president Mikheil Saakashvili -- an anti-corruption crusader leading protests against the government.