The Labour MP Yvette Cooper has criticised Twitter for "giving a platform to hatred and extremism" by being too slow to take down abusive content.
Cooper told the social media giant to "get its act together", urging a crack down on hate speech.
The call comes after the Crown Prosecution Service published new guidelines for prosecutors, telling them to treat hate crimes committed online the same as those committed in person.
In a letter to Twitter, co-written with the Fawcett Society, which campaigns for gender equality, Yvette Cooper highlighted examples of abuse targeted at prominent women such as shadow home secretary Diane Abbott and Labour's Luciana Berger, as well as anti-Brexit campaigner Gina Miller.
Cooper set up the cross-party 'Reclaim The Internet' campaign to challenge online abuse.
She called for Twitter to outline its plans to tackle abuse more quickly as research by the campaign found abusive posts remained online for days after being reported.
"Women are being routinely and regularly abused online with impunity for the abusers and that has to change."
A Twitter spokesman said: "Abuse and harassment have no place on Twitter.
"We've introduced a range of new tools and features to improve our platform for everyone, and we're now taking action on 10 times the number of abusive accounts every day than the same time in 2016.
"We will continue to build on these efforts and meet the challenge head-on."