Unlike those others, however, she was already in the Parliament as the member for Chisholm, centered on the Melbourne suburb of Box Hill, which she won as a Liberal candidate in 2016 before a spectacular fallout when she quit the party and moved to the crossbow over the leadership crisis and the bullying she witnessed in federal politics.
"It was a culture of terrible behavior that was an entrenched, anti-women culture," she said of what she saw in the Liberal Party last year.
"But also, the right wing of the Liberal Party has clearly created what I call parliamentary roadblocks in relation to issues such as climate change, and climate change action in my view is an urgent imperative."
"It was very frustrating to be in the Liberal Party and see the benefits of the National Energy Guarantee, and then seeing that basically being used as a trigger to blow up the government."
She will continue her electoral work for constituents in Chisholm until the election is called and she launches her formal campaign for Flinders, where she now lives with her husband after spending much of her childhood there.
Ms Banks said local residents in Flinders felt they were "taken for granted" by Mr Hunt and could not understand his decision to try to help Home Affairs Minister Peter Dutton become Prime Minister last August.
"They're especially angered at Greg Hunt's role in the leadership spill, in him being Peter Dutton's wingman and wanting to drop Malcolm Turnbull and Julie Bishop," she said.
Mr Hunt was one of the cabinet ministers who voted for Mr Dutton in the first leadership ballot on August 21 and then resigned to back Mr Dutton in the second ballot on August 24, which was won by Mr Morrison.
Ms Banks, a former lawyer and chief counsel at companies including George Weston Foods and GlaxoSmithKline, supports many of Turnbull's government's fiscal policies but breaks with the Morrison government on climate change policy.
She said she opposed Labor tax proposals including its changes to negative gearing on investment properties and its halt to cash refunds for shareholders who benefit from dividend imputation tax credits.
"This is a terrible proposal for people who do not necessarily have high income earners but want to be self-sufficient," she said of Labor changes to dividend tax rules.
"In relation to negative gearing, I oppose those changes. I believe it will affect housing markets and, again, it is not necessarily just high-income people who invest in the housing market. "
If she was elected and faced with the Parliament, she would have to support either the Labor or the Coalition, Mrs. Banks said she would make her decision on the "context at time" instead of indicating before which side she would back.
He said she wanted to issue an "open ticket" without advising voters to give their second preferences to one party or another, but she also said she would keep her options open to do the best for her campaign .
Speculation about Ms Banks has been building for months. She said she made her decision to run for Flinders over the summer, after her decision last year not to recontest Chisholm.
Mr Hunt said he had treated Flinders as "completely marginal" from the first day he had put himself forward to run for the seat.
"I've just walked 500 kilometers around the electorate and that's part of the passion of visiting 50 schools and 50 cities over a three-week period and working for autism, working and meeting families," he said on Wednesday.
Mr Hunt said he was fighting for better cancer services in the local area, an upgrade to the Rosebud Hospital and the electrification of the Baxter railway line.
"Labor is opposing the electrification at the state level of the railway to Baxter, which is short changing the Peninsula residents. So there are the things we're fighting for, "he said.
David Crowe is the Chief Political Correspondent of the Sydney Morning Herald and The Age.