Elon Musk engaged with right-wing activist Tommy Robinson on X, hours after the Prime Minister warned that social media “carries responsibility” for tackling misinformation which sparked disorder in parts of the UK.

Mr Musk, who owns the site formerly known as Twitter, responded with two exclamation marks to a post by Robinson – real name Stephen Yaxley-Lennon – commenting on the Prime Minister’s response to the disorder in the wake of the Southport stabbings.

The billionaire SpaceX and Tesla boss has had a controversial reign at X since taking over the company in 2022, and has been accused of allowing misinformation and other harmful content to flourish on the site since then.

On Thursday, Sir Keir had warned social media companies after misinformation spread online about the identity of the 17-year-old suspect, Axel Rudakubana, including false claims that he was an asylum seeker.

The Prime Minister said the Government would uphold the law everywhere, including online, where far-right groups have been accused of inciting violence and stirring division in the wake of the tragedy, which has led to unrest in Southport, London and Hartlepool.

Violent disorder, clearly whipped up online, that is also a crime, it’s happening on your premises, and the law must be upheld everywhere

Speaking directly to social media firms during a press conference in Downing Street, Sir Keir said: “Violent disorder, clearly whipped up online, that is also a crime, it’s happening on your premises, and the law must be upheld everywhere.

“That is the single most important duty of government, service rests on security. We will take all necessary action to keep our streets safe.”

Social media giant X has come under increased scrutiny since being taken over by Mr Musk in late 2022, with the billionaire himself engaging with misleading content and accounts known for spreading misinformation on a number of occasions.

In the last week he reposted a misleading video of US vice president Kamala Harris, and has previously engaged with accounts known to have spread misinformation on a number of topics, including Covid-19 and vaccine safety.

His approach to running the platform has been heavily criticised after he substantially cut staff numbers and changed the site’s verification and content moderation systems, saying he wanted to allow “absolute free speech”.

Under his leadership, the company has also restored the accounts of many figures previously banned for breaking site rules around hate speech, including in the UK such as Robinson and Katie Hopkins.

Since then, many users claim to have seen an increase in hateful content, as well as pornography and spam posts and accounts, despite Mr Musk claiming he would “defeat the bots” after taking over the company.

A number of experts have raised concerns about the rising levels of misinformation spreading on the platform, which they warned was being used by political activists to stoke divisions and tension.

One said this misinformation had been used by a “vocal minority” to sow division and “fuel their own agenda and trigger a summer of thrill-seeking impulsive insurrection” following disorder in Southport, London and Hartlepool in the days since the attack.

John Coxhead, a professor of policing at Staffordshire University, said groups were being “cynically stirred up by opportunistic populists with nothing better to do”.

In London on Wednesday, more than 100 people were arrested after protesters in Whitehall threw beer cans and glass bottles at police, and flares at the statue of Sir Winston Churchill in Parliament Square.

Demonstrators wearing England flags and waving banners saying “enough is enough” and “stop the boats” had congregated outside Downing Street, with chants of “We want our country back” and “Oh Tommy Robinson.”

In his televised address, the Prime Minister added that it was important for Government and tech firms to “work together” to keep the country safe, saying government “blaming everybody else and pointing fingers” does not work well.

Sir Keir said “there is a discussion to be had” about companies striking the “right balance”, saying social media “carries responsibility”, but that he wanted to “work together” to keep the country safe.

He added: “What has not worked well recently with the previous government, in my view, is the performative politics of a government blaming everybody else and pointing fingers. That approach to me is not effective.

“My approach is different, which is to roll my sleeves up, get the relevant people around the table and fix the problems, and meet the challenges that we have as a country.

“We did that with law enforcement and police this afternoon – similar approach with social media, which is not performative politics which gets us nowhere, but the politics of service, which is to actually work together to address the challenges that we have and make sure that we keep the country safe and respect the values of our fellow citizens, which are about law enforcement, security and safety.”