The deputy Labour leader has called for Tommy Robinson to be removed from YouTube, following his ban from Facebook.
Tom Watson describes Robinson, whose real name is Stephen Yaxley-Lennon, as “a violent, racist and Islamophobic campaigner”.
Following Facebook and Instagram’s ban of the former EDL leader, Mr Watson claims Robinson's followers “are transferring over their virulent hate to YouTube”.
Writing to Google’s CEO Sundar Pichai, who own YouTube, Mr Watson said: “YouTube’s policy on hate speech prohibits content which promotes violence or hatred against individuals or groups based on attributes including religion, race, immigration status or nationality. Many of his videos are clearly in breach of his policy.”
He added that social media companies “have failed to regulate hate speech and harm on their platforms”.
In January, YouTube removed all adverts on Robinson's channel to significantly reduce the revenue he can make from the videos, but the content is still available for viewing.
Robinson has increased his subscribers on YouTube from 294,000 on Wednesday to over 340,000 by Monday.
'Messages of hate'
On Wednesday, Damian Collins, chairman of the Digital, Culture, Media and Sport Committee, added his voice to those calling for Robinson to be removed social media platforms.
"His YouTube channel has hundreds of thousands of followers and includes films viewed by millions of people," he said.
"Far-right groups are exploiting social media to spread their messages of hate, and the YouTube 'next up' feature helps them by directing viewers to even more of this content once, as soon as, they start to engage with it."
YouTube operates a hate speech policy which removes content promoting violence or hatred against individuals or groups based on attributes including religion, race, immigration status or nationality.
The platform uses a strikes-based system, giving offending users a warning and removing individual videos, before going into a three-strike process that eventually leads to the channel being terminated if policies are repeatedly violated.
Responding to his Facebook ban on Tuesday, Mr Robinson claimed the "corrupt media and the establishment" were trying "to silence any opposition to their globalist plans".
He said: "I've breached no laws of Facebook, everyone is going to know that I've breached no rules, what I've done is shown people the truth and that is what they are removing, the truth. People will still find me.”