Senator Humphries says some party members have been unfairly ruled ineligible to vote in the preselection battle.
Long-time party member Ramon Montero has quit after being told he is not eligible to be a preselector.
"I do not support at the moment the secretary of the local Canberra Liberals because it's a disgrace what they've done," he said.
He says he believes the situation is connected to the preselection battle.
"The Liberal Party, until this situation arose several weeks ago, we were very united and all of a sudden they all broke loose when Mr Seselja challenged Mr Gary Humphries," he said.
But Canberra Liberals MLA Vicki Dunne says the rules are clear.
"To be a voting member you have to have attended a valid meeting in the past six months," she said.
She says the rules are being strictly enforced to ensure the preselection cannot be challenged.