But the move has sparked a furious backlash from across the Atlantic, with a close ally of President Donald Trump threatening to retaliate.

US Congresswoman, Anna Paulina Luna, cautioned the Prime Minister that she would be tabling legislation in the US Congress to "sanction not only Starmer, but Britain as a whole" if they attempted to ban X. She revealed the legislation was already being drafted and would "mirror actions previously taken by the US in response to foreign governments restricting the platform."

In 2024, America passed similar legislation to sanction a Brazilian judge who banned the app in South America. Ms Luna slammed any potential UK action as "a political war against Elon Musk and free speech – nothing more."

The incendiary threat marks a dramatic escalation in tensions between Sir Keir's government and Donald Trump's administration, which has repeatedly clashed with the Labour Prime Minister in recent weeks. The row erupted after Labour MPs and party officials, including chairwoman Anna Turley, demanded action against X over the disturbing AI-generated images.

Users have reportedly been instructing Grok to sexually exploit images of real people, including minors, prompting calls for urgent regulatory intervention. However, it is not believed similar action is being considered against other AI tools which can also manipulate images following user instructions.

Under pressure, X has begun halting some attempts to create non-consensual sexual images, but the feature will still be available for paying subscribers. Downing Street has condemned the move as woefully inadequate, with a No 10 spokesman blasting it as an insult to victims.

The spokesman told the Daily Telegraph the change "simply turns an AI feature that allows the creation of unlawful images into a premium service." They added: "It's not a solution. In fact, it's insulting to the victims of misogyny and sexual violence. What it does prove is that X can move swiftly when it wants to do so."

On Thursday, Sir Keir said Ofcom, the UK regulator, had his "full support to take action in relation to this," adding it was "unlawful." The regulator has extensive powers to restrict X's activities in Britain, including imposing hefty fines or blocking access to the platform entirely.

X currently has around 20 million users in the United Kingdom. Several MPs have already announced they are quitting the platform in protest over the AI image scandal. But the threat of US sanctions raises the stakes once again, potentially triggering a major row between Washington and Whitehall.