The Melbourne-based corporate executive will run as the Australian Sex Party’s candidate at the October 31 by-election against a field of seven other contenders.

Dr Doig hopes that campaigning in Polwarth will help raise her profile among voters across the Western District.

She has ancestral links to Colac but readily admits she has never lived in the Polwarth electorate.

"I'm reasonably familiar with the area. Having said that I wouldn't lie to people and say I'm a local. I'm not a local," she said.

The Liberal Party hold the seat by a 10.6 per cent margin, pushing an election victory for Ms Doig almost certainly beyond reach.

But with Labor deciding not to contest the byelection, Dr Doig says voters will now have a progressive choice with her representing the Australian Sex Party.

"I just hope that I can raise the profile of the Sex Party and make sure that people understand this is a progressive, sensible party despite the name," she said.

Dr Doig has been preselected by the party for a Senate seat in the federal election, which is expected to be held next year.

She served as a board director with the Port of Melbourne Corporation and Bakers Delight.

She played a major role in the push to have special religious instruction scrapped during school hours. But now she has the time to run for State Parliament.

"If it doesn't work out it's no skin off my nose," she said. 

Monash University politics professor Zareh Ghazarian says minor parties have been successful in getting elected at recent elections.

He says the Sex Party has a catchy name and stands a chance of winning a seat. "Certainly they are in it," he says.

But he added that the Sex Party will need to construct preference deals with the minor and major parties.

This will not be Dr Doig's first attempt to join the political arena. She previously made an unsuccessful attempt at Labor preselection.

But she let her Labor membership lapse after Julia Gillard committed $222 million to provide religious chaplains in state schools. Dr Doig was also a member of the Australian Democrats.

But she was most impressed by the Sex Party in the lead up to the last federal election in 2013.

"Just look at their policies. It's not just about sex. It's actually about commitment to getting religious zealotry out of public policy," she says.

Dr Doig also hails the Sex Party's support for civil and human rights, assisted dying and abortion services.

She has taken heart from the Sex Party's Victorian upper house MP Fiona Patten, who successfully led a push to establish buffer zones around abortion clinics to prevent protesters from harassing patients.

Dr Doig says she hopes she can deliver similar wins for her progressive agenda in the federal senate.

"Let's see if we can work together to take Australia forward," she said.