There will also be a review to see if existing laws are good enough to tackle online abuse, and a new code of conduct for social media like Twitter and Facebook will be drawn up in a bid to ensure it fulfils its potential as “a force for good”.
The Prime Minister will use a speech celebrating the heroism of those who fought to secure votes for women 100 years ago to warn that a “coarsening” of public debate and aggressive abuse hurled at people with opposing views is a “threat to our democracy”.
In Manchester, where the campaign for women’s suffrage was active and where leading “Suffragette” Emmeline Pankhurst was born and lived, she will recall how those campaigners faced down “fierce opposition” in pursuit of their rightful cause.
“As we remember the heroic campaigners of the past, who fought to include the voices of all citizens in our public debate, we should consider what values and principles guide our conduct of that debate today,” she is expected to continue.
“For while there is much to celebrate, I worry that our public debate today is coarsening, that for some it is becoming harder to disagree, without also demeaning opposing viewpoints in the process.
“In the face of what is a threat to our democracy, I believe that all of us – individuals, governments, and media old and new – must accept our responsibility to help sustain a genuinely pluralist public debate for the future.
“A tone of bitterness and aggression has entered into our public debate.
“Participants in local and national public life, from candidates and elected representatives to campaigners, journalists and commentators, have to contend with regular and sustained abuse,” she will lament, highlighting that political candidates who are female, black, minority ethnic or gay are “disproportionately targeted”.
She will say that social media companies have made progress but must “step up” and do more to stop their sites hosting some of the most “troubling” instances of abuse which she will say can put people off getting involved in politics.
The Government will create a new annual “internet safety transparency report” to track firms’ progress in stamping out online abuse.
It will include information on how much harmful content is reported to companies, how much of it they remove, how they handle complaints and what they do to stop harmful and abusive behaviour appearing online in the first place.
She will further promise to publish an Internet Safety Strategy this spring, and later this year to introduce a “comprehensive” new code of practice for social media which firms will be encouraged to sign up to.
It will spell out minimum standards and will include developing “robust community guidelines” for what site users upload and do on line; preventing abusive behaviour on line; and action to identify and stop people who persistently misuse services.
Companies will also have to spell out their reporting mechanisms and policies for removing inappropriate, bullying and harmful content and guidance to help users report illegal online activity.
The Prime Minister will also announced a review by the Law Commission of the criminal law relating to offensive online communications to ensure it can meet the challenges posed by the new technology which has grown up since the legislation was devised, including ensuring that what is illegal offline is also illegal online Mrs May is expected to conclude: “As the woman at the head of our country’s government, a century after my grandmothers were first given the right to vote, my mission is clear: to build that better future for all our people, a country that works for everyone, and a democracy where every voice is heard.”
The speech comes amid ongoing concern about abuse sent online to political opponents and about child abuse and terrorist content that has proliferated on the internet.