Outspoken former MP Ross Cameron faces being suspended from the Liberal party for five years, following a television interview in which he savaged Treasurer Gladys Berejiklian.

In an interview with Sky News last month, Mr Cameron accused the Treasurer of sabotaging the party's prospects of democratic reform, because she was either committed to authoritarian rule or manoeuvring to replace Mike Baird as premier.

Mr Cameron made the comments shortly before the state Liberal party plebiscite issue was due to be debated by the NSW state council.

The NSW Liberal party executive voted on Friday night to give Mr Cameron 28 days to show cause why he should not be suspended from the party, which forbids members from discussing party matters with the media.