The spat risks complicating the government’s efforts to get social media companies, including X, to be more proactive in removing disinformation believed to be stoking the riots.
It came on a seventh day of disorder with far-right and anti-racism protesters facing each other in Plymouth, separated by a line of police officers. Devon and Cornwall police said one of their vans was damaged and officers were met with “a level of violence”.
In Birmingham, hundreds of Muslims, including men in balaclavas and masks, formed a protective ring around a local mosque and shops amid rumours of a planned march by the far-right.
Meanwhile, Malaysia, Indonesia, Nigeria and the United Arab Emirates - all of which have majority Muslim populations - as well as Australia, issued travel alerts telling their citizens to be careful if they were travelling to the UK amid the riots.
However, Downing Street rebuffed calls for the army to be deployed or parliament to be recalled in response to the clashes, seen in at least 16 British towns and cities in the last week.
Starmer was also forced to respond to claims there was “two-tier policing” in Britain after Nigel Farage suggested riots over the last week had been dealt with more harshly than other recent unrest and protests.
The prime minister rejected the claims, and Sir Mark Rowley, the Met Police commissioner, was forced to deny that he had intentionally knocked a microphone out of a reporter’s hand when asked about the issue.
The government has accused social media companies of fuelling the protests, which were prompted by false claims spread online that the suspect in the killing of three girls in Southport was an asylum seeker.
Downing Street said on Monday action taken by social media companies to tackle misleading and inflammatory material “doesn’t go far enough”.
It also warned some foreign state actors were amplifying online disinformation.
‘Hateful misinformation’
Science Secretary Peter Kyle held one-on-one talks with executives from X, YouTube, Meta, Google and TikTok about the “spread of hateful misinformation and incitement” regarding the riots, insisting action must be taken “at pace”.
Musk is one of the US’s most influential tech bosses, also owning the electric car company Tesla. He is supporting Trump’s bid for the US presidency this year.
He has commented on X more than a dozen times in recent days about the UK riots.
In one post, he responded to footage allegedly from the UK that showed rioters, some masked, launching fireworks in clashes. He responded “civil war is inevitable” to a message about the video.
Later, he responded to a message shared by Starmer’s official account which said “we will not tolerate attacks on mosques or on Muslim communities”.
Musk wrote back: “Shouldn’t you be concerned about attacks on *all* communities?”
The exchange seemed to be in response to Starmer’s announcement on Sunday to offer additional security personnel to mosques at risk of being targeted.
Musk was previously criticised for reinstating the accounts of far-right figures including Tommy Robinson, whose real name is Stephen Yaxley-Lennon, in November last year. In one post about the riots, Musk responded to footage shared by Robinson.
Downing Street condemned Musk’s “civil war” comment.
The prime minister’s official spokesman said on Monday: “There’s no justification for comments like that, and what we’ve seen in this country is organised thuggery and has no place either on our streets or online.
“As the home secretary said this morning, we’re talking about a minority of thugs that do not speak for Britain.
“And in response, we’ve seen some of the best of our communities, coming out and cleaning up the mess and the disruption of those that don’t speak for our country.”
Kyle said after holding talks with tech giants: “There is a significant amount of content circulating that platforms need to be dealing with at pace.
“Different companies take different approaches, and I expect platforms to ensure that those seeking to spread hate online are not being facilitated and have nowhere to hide.”
Meanwhile, Starmer faced some criticism from senior Tories for not calling a Cobra meeting quickly enough about the riots. One was eventually held on Monday.
James Cleverly, who is running for the Tory leadership, said the government “should have been quicker” in its response to riots taking place across England.
No 10 rejected the criticism.