A Sydney councillor is set to be suspended from the NSW Liberal Party for giving a radio interview critical of elected party officials, including claiming one has a criminal record.

Internal party documents obtained by Fairfax Media show members of the Liberal's powerful state executive voted on Monday to suspend Liverpool councillor Peter Ristevski for comments made during a free-ranging and explosive radio interview early this month.

The vote follows a long-running and ugly battle for control of a party branch in the western suburbs.

Cr Ristevski and allies recently attained control of the party's Moorebank branch, at the expense of his colleagues and rivals, Holsworthy MP Melanie Gibbons and Liverpool mayor Ned Mannoun.