New Liberal MP and former party president Trent Zimmerman has denied he was making discriminatory comments by saying some ethnic communities engaged in branch stacking after a party member filed a complaint with the Human Rights Commission.

Speaking at last month's party conference on whether the Liberals should move toward a plebiscite model for pre-selecting candidates, North Sydney MP Mr Zimmerman spoke of the downsides to a proposed new preselection model including opening votes to groups responsible for branch stacking including ethnic communities.

In a piece published by Fairfax Media shortly before the conference, Mr Zimmerman noted that the party had previously seen conflict after hundreds of members of some Middle Eastern communities joined party branches.

Party member Magdi Mikhail has since filed a complaint with the Human Rights Commission.