He said offering voters a new holiday was a "cynical" move.
"MPs can take one simple, costless action to help the climate and the taxpayer."
A recent poll was ACT's best in 17 years.
Stephen Berry stepped down on Sunday afternoon.
"I am a minority. I've been a minority of one in Parliament for the last five years."
"They're telling one side of the story with your taxes and that's wrong."
Newshub can reveal the video he told supporters would make them "lose their proverbial".
A pamphlet showing David Seymour playing a traditional Chinese instrument is just the beginning.