Elon Musk’s post on his social media platform that “civil war is inevitable” as rioting in the UK continues is “deeply irresponsible”, justice minister Heidi Alexander said.

Mr Musk, the head of X, formerly Twitter, has faced a backlash to his comments as social media sites have also been criticised for not doing enough to tackle the spread of disinformation.

Ms Alexander told Times Radio: “If you have got a platform, a large social media platform, then you have also got a responsibility.”

She said it was “deeply irresponsible” and that “everyone should be appealing for calm”.

“Use of language such as a ‘civil war’ is in no way acceptable. We are seeing police officers being seriously injured, buildings set alight, and so I really do think that everyone who has a platform should be exercising their power responsibly,” Ms Alexander said.

Prime Minister Sir Keir Starmer’s official spokesman said on Monday that there was “no justification for comments like that”.

“We’re talking about a minority of thugs who don’t speak for Britain,” he said.

Michelle Donelan, a former Conservative MP who worked on the Online Safety Act when she was technology secretary, criticised Sir Keir for “going off on one at Elon Musk”, saying the Prime Minister should focus on engaging with social media platforms.

She told GB News: “I don’t think he’ll do anything in relation to social media.

“We’ve done the Online Safety Act, which is the most comprehensive Bill in this space in the world.”

Offences around incitement in UK law were in place long before the social media age, and fall under the Public Order Act 1986, but stronger measures are on the way in the form of the Online Safety Act, which passed into law in 2023 but is yet to come into full effect.

It will require social media firms to take more robust action against illegal and harmful content and activity on their platforms.

But Sir Keir’s spokesman said on Monday that social media firms have a responsibility to make sure their users are safe and that criminal activity is not being posted on their platforms.

He said: “They shouldn’t be waiting for the Online Safety Act for that.”

A mosque in Southport and a Citizens Advice office and police station in Sunderland are among buildings that have been damaged during days of clashes between anti-immigration demonstrators, police and counter-protesters.

Ms Alexander also said the Government was taking a “very robust approach” to social media companies and that being behind a computer or mobile phone screen would offer no protection from the law.

The justice minister told Sky News: “There has been some welcome action where there has been automated removal of some false information, but I do think the social media companies could and should be doing more.

“They have got a moral responsibility not to be propagating and disseminating misleading and inflammatory content on their platforms.”

On Monday, Technology Secretary Peter Kyle said he had met representatives from TikTok, Facebook’s parent company Meta, Google and X “to make clear their responsibility to continue to work with us to stop the spread of hateful misinformation and incitement”.

Home Secretary Yvette Cooper said the Government would not tolerate “armchair thuggery” and that social media platforms needed to take responsibility for the spread of online misinformation which has fuelled much of the disorder.