Elon Musk has said UK MPs “will be summoned to the United States of America to explain their censorship and threats to American citizens” in a fresh escalation of tensions between the world’s richest man and Labour.

Musk, who has been a fixture at the side of Donald Trump since his re-election as US president, was responding to a Guardian report on Wednesday that the Commons’ science and technology select committee would call him to give evidence in the new year in its inquiry into the spread of harmful content on social media after the August riots.

The committee’s chair, Chi Onwurah, a Labour MP, said she wanted to see how Musk, who owns the X social media platform, “reconciles his promotion of freedom of expression with his promotion of pure disinformation”.

X hosts accounts by figures including Tommy Robinson and Andrew Tate, who were accused of inciting people to join Islamophobic protests.

Musk, who has more than 205 million followers on X, responded by saying the MPs would be summoned to the US. He has previously complained that prison sentences handed down to people who stoked the riots on X are a breach of free speech rights and said: “I don’t think anyone should go to the UK when they’re releasing convicted paedophiles in order to imprison people for social media posts.”

He has labelled the British prime minister “two-tier Kier”, alleging that not all communities were equally protected by police in the UK, while Jess Philips, a government minister, has labelled X “a place of misery”.

Musk weighed in on changes to inheritance tax on farms by saying on Monday that “Britain is going full Stalin”. Peter Mandelson, who is tipped to become the next UK ambassador to Washington, then called for an end to the “feud” between Musk and the UK government, calling him “a sort of technological, industrial, commercial phenomenon” with whom the UK must build bridges.

Related: How Elon Musk became Donald Trump’s shadow vice-president

In an interview with the Guardian on Thursday, Peter Kyle, the secretary of state for science and technology, denied there was a feud and called Musk “an innovator of extraordinary proportions, the like of which our globe, our humanity, very rarely sees”.

He said he was ready to have “a frank conversation where we disagree, but also strive to find common ground”.

However, Kyle added: “The way that he has characterised British society is wrong. I would love to have a conversation with him about how, with his view of free speech, we can keep people safe. Free speech, in my view, doesn’t include the right to sow either misinformation or hatred to a degree that damages either people or communities … as happened in August and that led to arrests because that was criminal activity.”

Kyle said he was “in touch with X” and has had “many conversations with them about the nature of free speech and how it should be applied”. He also said he had “no plans to go off X, simply because I respect so much of the audience that’s there and I do want to communicate with”.

It was not immediately clear to what “threats to American citizens” Musk was referring in his call for British MPs to be summoned to Washington, but one of his US-based online followers claimed, without providing evidence, he was called by British police and threatened with charges if he did not take down certain posts during the riots.

Another follower described the MPs’ wish to call Musk to give evidence as a trap, saying: “They’ll detain him at the border, demand to see the contents of his phone, and charge him under counter-terrorism laws when he refuses.”

Asked about Musk’s response, Onwurah said: “X is one of the most relevant social media platforms to our inquiry. We want to hear from senior figures at the company so that we can gather the best evidence possible. And Mr Musk is the most senior representative of X, with strong views on misinformation as well as freedom of expression, an important subject in its own right.”

Musk has started calling himself “first buddy” in relation to the president-elect and has been given the job of reforming US government efficiency. It appears he will have considerable influence on the regulation of artificial intelligence, especially considering he owns an AI startup, xAI, which has attracted billions of dollars in investment from the Qatar sovereign wealth fund and Silicon Valley private equity giants.