Politicians are guilty of a “dereliction of duty” by failing to ensure the tech revolution has worked for everyone in society, Sadiq Khan will warn.
The London mayor will urge the likes of Facebook and Twitter to improve their response to criticism, or face the possibility of further regulation.
Mr Khan will also warn Uber and other tech firms that all companies “must play by the rules” in the markets in which they operate.
The Labour mayor is the first British politician to give a keynote speech at the South by Southwest conference in Texas.
Mr Khan is set to accuse politicians and governments of “sitting on their hands while the tech revolution has happened around them”.
He will add: “It must ultimately fall to government – working with tech businesses and leaders – to ensure that this revolution is not detrimental to our long-term progress.
“There’s been a dereliction of duty on the part of politicians and policymakers to ensure that the rapid growth in technology is utilised and steered in a direction that benefits us all.”
Mr Khan is expected to read out some of the racist, abusive and illegal tweets that he has received since becoming mayor.
He will also raise concerns over social media’s role in influencing elections and referendums, spreading fake news and enabling extremists to radicalise and brainwash others.
“Facebook, Twitter and other platforms are finally starting to react to the criticisms and are developing technology to make sure the reporting process becomes quicker and more effective,” he is expected to say.
“But with the skills and resources these companies have at their disposal, I believe it’s possible to go further and faster.”
If this does not happen, Mr Khan will say that more countries “will start to follow or go further than what Germany has done”.
Mr Khan will also hint at his ongoing row with Uber, with Transport for London having refused to renew the taxi service’s licence in September.
Mr Khan will say that in some cases innovation and the sharing economy “risks being used as cover to break-up decades of established and hard-fought rights”.
He is expected to say: “There must be greater responsibility taken by some tech companies for the impact they’re having on the world.
“And, crucially, no business or industry should ever consider itself above the local rules, or laws set by democratic processes.
“In London, we’ve been clear with Uber and other companies that everyone, no matter how big or small, must play by the rules. No exceptions.
“Our economies have always needed new regulations in place to meet the needs of workers and consumers when the environment changes. Evolving economies must mean evolving regulation, and today is no different.”