MPs who abuse or sexually harass women must be “held to account”, Labour leader Jeremy Corbyn will say later.
M Corbyn will speak out against “a culture where the abuse of women has often been accepted and normalised,” including at Westminster.
It comes as Downing Street described allegations of sexual harassment in politics as “deeply concerning”.
Mr Corbyn will also reject claims he was too slow to suspend a Labour MP for misogynistic and homophobic comments.
On Wednesday, Sheffield Hallam MP Jared O’Mara was suspended by Labour while the party investigates online remarks he made from 2002 to 2004.
Labour had initially said it would not be suspending the MP while the allegations were investigated.
In a speech at the Unite union’s Scottish policy conference later, Mr Corbyn will say that in the wake of allegations about movie mogul Harvey Weinstein, the issue of sexual harassment is not one confined to Hollywood.
“Misogyny and sexism are widespread problems across society,” he will say.
“Sexual abuse and abusive treatment of women by men is not confined to any one industry, workplace or institution.
“The problem doesn’t stop with those who make unwanted advances on women.
“It’s a warped and degrading culture that also exists and thrives in the corridors of power, including in Westminster.”
Mr Corbyn will also encourage women who have been abused or harassed by MPs to speak out, adding that he would not tolerate any form of discrimination or harassment in the Labour Party.
His speech comes amid reports that female researchers and aides in Parliament have been using a WhatsApp group to share information about alleged abusive behaviour by MPs from both the main parties.
And on Saturday, the Times reported that four male MPs, including a minister, have been accused of harassing or propositioning young women inappropriately.
The prime minister’s official spokeswoman said any report of sexual harassment were “deeply concerning” and urged anyone with information to contact the authorities.