Right to Life Australia senior executive officer Katrina Haller said the pro-life group would throw its support behind the balance-of-power MP, who became an online sensation last week, inspiring the term "tummy eggs".

She said the group would actively campaign against pro-choice Liberal candidate Sean Armistead and Labor candidate Helen Constas.

They plan to door-knock Frankston residents and hand out 'how to vote' cards in the marginal electorate, which is held by Mr Shaw by a slender 0.6 per cent margin following the redrawing of electoral boundaries.

"We congratulate Geoff Shaw, he is one of the only politicians who has the guts to do something about abortion. He wants to ban partial abortions, gender-selection abortions and allow doctors to have a freedom of conscience."

It comes as non-partisan, youth-based women's rights group Vocal Majority announced on Monday it would run a grassroots campaign to unseat Mr Shaw.

The group's co-founder Courtney Sloane, who is a member of the Labor Party, said the controversial MP was holding women's health to ransom.

"We really don't want to see a situation where he chips away at tiny bits of legislation and our pro-choice legislation is completely eroded."

She said the group would door-knock residents in the Frankston electorate and launch a social media campaign against the maverick MP, who has vowed to overhaul the state's abortion legislation.

"We will make it clear who is pro-choice. We want to tell people what Geoff Shaw stands for."

Last week, Mr Shaw revealed he would introduce a private members' bill that would outlaw gender selection and partial birth abortion, and force doctors to resuscitate babies who survive abortion attempts.

The Age revealed last week that Mr Shaw would travel to the US on a taxpayer-supported study tour to investigate abortion laws.

A spokesman for Mr Shaw did not want to comment.