I warmly welcome the intervention made yesterday by Momentum chair Jon Lansman on the antisemitism damaging our party. Jon told BBC Radio 4’s Today programme that “online Facebook groups can become an arena in which a minority with hardcore antisemitic views can infect” Labour members. Unfortunately, he is right.

As revealed by a Sunday Times investigation last year, 400,000 people are members of Facebook groups supportive of Labour. Many of these groups reportedly contain holocaust denial, praise for Adolph Hitler, antisemitic conspiracy theories, as well as violent threats against politicians.

Most of the people who wrote those disgusting things are probably not members of our party. But the point Jon was rightly making is that social media forums like Facebook groups act as echo chambers, where extremist views can quickly become normalised and widespread.

An article in a national newspaper which questioned the facts of the holocaust would be criticised and met with a reiteration of the tragic reality of the genocide. If someone told a group of friends that a small family of Jewish bankers controlled the world’s governments, they would be laughed at, and challenged, rather than treated seriously.

Facebook groups often don’t work like this. Any posts which goes against the grain will likely be harshly criticised and could see the user excluded from the group, while posts which reinforce existing narrow views will receive far more likes and positive comments than the poster would ever see on their personal profile.

Jon also said this morning that, due to our large and younger membership, “the role of social media in fomenting and spreading this poison is therefore more of a problem in the Labour Party” than the Tories. I agree in terms of the scale of the problem, given our mass-movement party, though this is certainly not just a problem for Labour. The Guardian has previously reported on a pro-Conservative Facebook group full of “Islamophobic, homophobic and racist comments”. Meanwhile, the resurgence of the far-right in Britain is largely fuelled by its efforts on social media, and the US alt-right was born out of forums like 4Chan.

It goes beyond politics too. Secret Facebook groups used to spread revenge porn and misinformation about medical practices have been recently exposed. Hate, radicalisation and misinformation is not confined to explicitly political spaces, but affects wider society.

It’s time to properly regulate social media and prevent it being used to poison us with fake news and intolerance. That’s why I introduced a bill to do just that in parliament last year, and why colleagues from across parliament are calling on the government to allow it to be debated and voted on at the next available opportunity.

The bill would make administrators and moderators liable for the content on their site, making people think before they post, or allow a post that could be damaging. Jon Lansman spoke an uncomfortable truth for some in our party yesterday. Alongside the words of Tom Watson over the weekend, we are seeing leadership to tackle the abuse and hate in our party. My bill would allow us to take further steps to root it out.