Downing Street today said Twitter must continue to protect its users after billionaire Elon Musk bought the platform.
The world’s richest person completed the $44bn deal with a promise to reduce censorship on the platform.
The prolific Twitter user describes himself as a “free speech absolutist” - raising fears it could become a platform for hate speech.
Asked for Boris Johnson’s reaction to the takeover, the prime minister’s official spokesman said: “I think regardless of ownership, all social media platforms must be responsible.
“And that includes protecting their users from harm on their sites.
“Obviously, it is too early to say what if any changes will be made to how Twitter operates.
“It remains an important tool. It’s used by world leaders and we will continue to work with them to make sure it continues to improve.”
Some human rights groups have raised concerns that a lack of moderation could lead to a rise in hate speech.
Others are calling for accounts suspended by the company - such as former US president Donald Trump - to be allowed back.
Asked if the prime minister would like to see Trump return to the site, he replied: “That’s not a question I’ve asked him. I think that’s a matter for Twitter.”
Musk, the Tesla and SpaceX boss, has pledged to boost free speech on the platform so it can fulfil its potential as the world’s “digital town square”.
Twitter founder Jack Dorsey welcomed the takeover of his company but some staff have reacted with horror.
Andy Burrows, the head of child safety online policy at children’s charity the NSPCC said urgent clarity was needed over what approach a Musk-led Twitter would take to tackling online abuse.
“There’s a huge difference in outcomes between a platform that tackles online sexual abuse versus meeting basic legal requirements,” he wrote in a tweet.
US senator Elizabeth Warren, described the deal as “dangerous for democracy”, adding: “Billionaires like Elon Musk play by a different set of rules than everyone else, accumulating power for their own gain.”
However, Ayaan Hirsi Ali, a human rights activist and founder of the AHA Foundation, which works to liberate women and girls from cultural practices that violate their human rights, welcomed Musk’s purchase.
“Elon Musk now owns Twitter. It is a great day for Free Speech,” she tweeted.
“Let’s celebrate”.