Boris Johnson has condemned both Twitter and Instagram for failing to act quickly enough to remove anti-Semitic posts by grime star Wiley.

As No.10 warned that it was determined to introduce new laws protecting users of all social media platforms, the prime minister’s spokesperson said he wanted big tech firms to go “much further and faster” in removing hateful content.

Wiley, who has half a million followers on Twitter, has been suspended for seven days following a stream of rambling, abusive tweets that targeted Jewish people.

Twitter is being subjected to a two-day boycott by leading politicians and commentators in protest at its failure to suspend the grime artist more swiftly and for not booting him off the platform completely.

Home secretary Priti Patel has now written to Twitter and Instagram demanding answers on why a string of hateful posts were allowed to remain in place for hours and in some cases days.

“The PM would echo the comments of the home secretary yesterday,” the spokesperson said. “We expect a full response.”

“Anti-Semitic posts from Wiley are abhorrent…This material should not have been able to remain on Twitter and Instagram for so long.

“Social media companies need to go much further and faster in removing hateful content such as this. The message is clear: Twitter needs to do better on this.”

The anti-Semitic content posted by Wiley, whose real name is Richard Cowie, is also being investigated by the Metropolitan Police, with a spokesperson saying that the “relevant material is being assessed”.

Among the abuse posted were suggestions that Jews should be shot, that a mixed race Jewish woman was “not Black” and retweets of messages from Holocaust deniers.

The spokesperson explained that the PM had decided not to join the boycott of Twitter because “it’s important to that during the pandemic that we continue to communicate important public health messages”.

“But at the same time we have set out very clearly that Twitter’s performance has not been good enough in response to the anti-Semitic comments made by Wiley and it needs to do much better.”

No.10 warned that it was currently consulting on much tougher measures to police big tech firms with new ‘online harms’ legislation. 

“What we are seeking to do is deliver the most comprehensive regime to tackling online harms anywhere in the world,” the spokesperson said, adding a full government response would now take place “this autumn”.

“This will be followed by new laws which place duty of care on online platforms to ensure they keep their users safe.”

Using the hashtag #NoSafeSpaceForJewHate, campaigners have accused Twitter of “ignoring anti-Semitism” after offensive remarks on Wiley’s account were still visible 12 hours after they were first posted.

Britain’s Chief Rabbi Ephraim Mirvis said he would take part in the protest, having already written to bosses at Twitter and Facebook to tell them: “Your inaction amounts to complicity.”