Yvette Cooper will warn that increasing levels of online abuse directed at women risks putting them off joining the Labour Party.
The former shadow home secretary is expected to call for the Opposition to do more to challenge online misogyny and for rules on tackling bullying or sexism in party meetings to include online harassment.
She will warn sexist abuse is "increasingly masquerading as political activism" - including in the general election, Scottish independence referendum and Labour leadership contest - as she outlines wider plans to create a Commission on Women and Technology.
Ms Cooper will use Labour's women's conference to announce the body's first area of work will involve a new campaign seeking to prevent women from being "drowned out by vitriol and hate" and to tackle online bullying.
Compulsory sex and relationship lessons should take place to teach children about social media and the need for respect both online and offline, Ms Cooper will say.
She will also call for the Government to collect more data to understand the scale of misogynistic abuse in the country and to launch a new campaign against online abuse.
The former Labour leadership contender will say: "In the end this isn't about experienced politicians like me, Liz (Kendall), Stella (Creasy), Angela (Eagle), Caroline (Flint) or Harriet (Harman) - we're never going to be silenced by the high-tech equivalent of angry letters written in green ink that politicians have received for centuries.
"But the scale of abuse directed at those who retweeted us or supported us will put women off joining the Labour Party in the first place and getting involved. We mustn't let that happen.
"Unless misogyny on the internet is challenged, more women's voices will be silenced, and more women will be oppressed or feel prevented from speaking out just as if we'd gone back to the Victorian age. We cannot let that happen.
"That's why the first piece of work from the new Commission on Women and Technology I am setting up will be a major new campaign for women's voices - in politics, in the media and in business.
"We must not stand on the sidelines as women's voices are drowned out by vitriol and hate."