The UK’s chief rabbi, Ephraim Mirvis, has accused Facebook and Twitter of complicity in antisemitism through inaction as he urged both platforms to do more to tackle hate speech after an antisemitic tirade last week from the grime musician Wiley. In a letter to the technology companies’ chief executives, Mark Zuckerberg of Facebook and Jack Dorsey of Twitter, Mirvis said “the woeful lack of responsible leadership … cannot be allowed to stand. “Your inaction amounts to complicity. I urge you to take swift action to challenge the hatred that currently thrives on your platform.” The chief rabbi, along with many other social media users, were boycotting both platforms, as well as Instagram, for 48 hours starting on Monday morning, he said, in protest. The protests were prompted by a series of tweets and Instagram posts from Wiley calling for Jews to be shot, and for black people to go to “war” with Jewish people. The messages, initially sent on Friday and Saturday, remained live on both sites for many hours. Wiley received a temporary suspension from Twitter, first for a few hours between the Friday and Saturday posts, and then for a full week. But while the most explicitly hateful tweets were removed by the site on Saturday, it took longer for the majority of the posts to be taken down, and Wiley’s account remains live on the site. Many of the tweets appear to have been removed by Wiley, rather than being taken down by Twitter for violating its rules. A spokesperson for the Campaign Against Antisemitism, which is organising the Twitter walkout, said Wiley “clearly has deeply held antisemitic beliefs based on unhinged conspiracy theories that in our experience are indicative of long-term exposure to Jew hatred. “Instead of acting immediately to close down Wiley’s accounts, Twitter and Facebook have decided to protect this racist, with Twitter deleting only a few token tweets and leaving most of Wiley’s incitement to racial hatred online. “They have decided to allow a racist to continue to use their platforms to reach hundreds of thousands of people. That is why we are walking out from these social networks and we are heartened to see so many decent people standing with us in doing the same.” In a statement, a Facebook spokesperson said: “There is no place for hate speech on Instagram. We have deleted content that violates our policies from this account and have blocked access to it for seven days.” The walkout comes while Facebook is in the midst of another boycott over its failure to tackle hate speech. A coalition of advertisers, including the consumer goods company Unilever, the carmaker Volkswagen and The North Face clothing company, have committed to no advertising on the social network or its sister sites for the month of July as part of the Stop Hate for Profit campaign, organised in the US. Almost a third of major advertisers had signed up to the boycott by the end of June, prompting a series of concessions from the social network. But without the support of small advertisers, which make up the bulk of the company’s revenue through weight of numbers, the boycott has little chance of affecting Facebook’s bottom line, leading Zuckerberg to dismiss its importance in a private conversation with staff. “My guess is that all these advertisers will be back on the platform soon enough,” he said in a transcript of the comments obtained by the tech news site the Information.