Theresa May has warned that online abuse and intimidation is threatening Britain's democracy, as she hails the "heroism" of the suffragettes who won the vote for women 100 years ago.
On the centenary of the 1918 Representation of the People Act, which granted the vote to many women aged over 30, May set out plans to counter the online "bitterness and aggression" which is deterring many from engaging in political debate.
In a speech in Manchester to mark the 100-year milestone, the Prime Minister will announce plans for a Law Commission review to ensure that laws against abuse and intimidation are updated to govern social media.
She will also pledge to establish a new annual internet safety transparency report, to provide data on how social media companies are dealing with abusive material, and endorse the recommendations of a report into intimidation produced last year by the Committee on Standards in Public Life, which called for legislation to shift the balance of liability for illegal content onto the social media companies.
A social media code of practice will be released later this year, while the Government will publish its Internet Safety Strategy in the spring.
The Prime Minister is expected to say: "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."
And she will add: "While there is much to celebrate, I worry that our public debate today is coarsening."
May will later address a reception in Parliament to launch a year-long Vote 100 programme of events to celebrate a century of female suffrage.
All female MPs past and present have been invited, in what is expected to be the largest gathering of the UK's women politicians ever organised.