Green Leader Annamie Paul has been given an ultimatum by party members.
If she doesn't repudiate past remarks from a former adviser about the Israeli-Palestinian conflict and reiterate her support for the Green caucus, she will face a non-confidence motion next month.
Lia Renaud resigned as one of the federal council's 15 members last night, saying she could not continue supporting Paul, but that she is still backing Green MPs Elizabeth May and Paul Manly.