Two MPs, Julie Anne Genter and Annette King, claim Parliament's Speaker, David Carter, treats women MPs unfairly compared to their male colleagues.
The allegations were made on TV ONE's Q+A programme, during a discussion on sexism in politics sparked by former Kiwis rugby league coach Graham Lowe calling Labour MP Jacinda Arden "a pretty little thing".
Green MP Ms Genter said she faces disrespect in Parliament, particularly when Mr Carter is "unconsciously" harder on women during proceedings.
"I do think that the current speaker, unconsciously, is harder on women, cuts off women, is less likely to treat their points of order seriously... than men," she said.
Labour deputy leader Annette King said she agreed with the claim but has found the treatment of women in Parlimanent is better than in the days of Robert Muldoon's leadership.
"I'm not saying it's great, but it is certainly better," she said.
National MP Judith Collins said she believes the Speaker hears male voices more clearly than female voices.
Ms King also said Prime Minister John Key showed gender bias in his handling of two seperate scandals involving minister Murray McCully and former minister Judith Collins.
"She was treated differently," Ms King said in reference to Ms Collins.
"It was obvious. Murray should've been treated the same - he should have been stood down while there was an inquiry. He wasn't and I think that shows a bias in his favour."