As denizens of the Westminster bubble lathered in more details from the Peter Mandelson saga on Monday, another intriguing story was pushed further down the news agenda than it otherwise might have been.Shabana Mahmood, the UK’s home secretary, withdrew authorisation to travel to the UK for two US-based left-wing political activists and media commentators, Cenk Uygur (56), co-founder of online news show The Young Turks, and his nephew, streamer Hasan Piker (34).Both are serial critics of Israel. Both view themselves as victims of a growing UK crackdown on freedom of speech at the behest of supporters of the Jewish state.The move to effectively ban both men from the UK – technically they could still apply for visas – was justified by the UK’s Home Office on the basis that their presence in Britain “may not be conducive to the public good”. That is all the UK government will say.Speaking to The Irish Times the day after he was prevented from travelling, Turkish-born US citizen Uygur said he had travelled to the airport in Los Angeles to board a flight to London. He and Piker were booked to speak separately at the SXSW London conference, while Uygur was also scheduled to speak at an event at Oxford University. He is a frequent visitor to the UK, and a regular on the YouTube show of Piers Morgan.“The airline staff said they had a problem trying to check me in. They went off to check something and then they told me that my ETA [electronic travel authorisation] had been suspended, although I could see it said ‘rejected’ on the screen,” said Uygur.The same thing happened to Piker.Uygur, who spoke at a Cambridge event last year, said he had received no advance notice from the UK government that it planned to remove his permission. He says that soon after the incidents, a story appeared on the website of the British newspaper The Times with details of his and Piker’s travel refusals. The well-briefed piece was written by a Times reporter who covers the Home Office. It cited “fears they could fuel anti-Semitism”, as well as their statements on Israel.Mahmood has cultivated a reputation as a hardline home secretary, enacting strict immigration reforms while also taking a muscular approach to border issues. Last month she banned 11 people from travelling to Britain for Tommy Robinson’s hard-right Unite the Kingdom protest. Some of them were elected politicians.[ Tens of thousands march in London in separate far-right and pro‑Palestinian protestsOpens in new window ]Piker’s exclusion from Britain was publicly called for last week by Labour MP David Taylor, a frequent supporter of pro-Israel causes in the UK parliament, as well as the Community Security Trust, a British Jewish group.Past comments from Piker, who has three million Twitch followers, have included that the Palestinian group Hamas, which perpetrated the October 7th terrorist attack, was “a thousand times better than Israel”.While you don’t have to dig too deep into Piker’s past comments to find examples that Mahmood could plausibly use as cover for her decision to ban him, Uygur, whose show has 6.6 million YouTube subscribers, seems a different case.The initial well-briefed story by The Times cited Uygur’s references to Israel’s actions against Palestinians as “barbaric”. However, many of Mahmood’s Labour parliamentary party colleagues regularly use similar language about Israel in private – I have heard them say such things myself on the terrace behind Strangers’ Bar in the House of Commons.Some even say it in public. Labour MP Afzal Khan, for example, has described an Israeli suggestion to forcibly displace Palestinians in Gaza as “barbaric”.The story in The Times also cited Uygur’s description of Israel’s actions in Gaza as “genocide”. Yet this view is also shared privately by many in the Labour parliamentary party. It is also the official position of several governments, including the Republic’s.Uygur insists he has never been anti-Semitic, and is merely a critic of the state of Israel.“Were we really going to cause such disorder by speaking in Britain that they had to ban us? I was there last year and there was no disorder,” said Uygur. “The truth is that there is only one country now that you cannot criticise: that is Israel.”The wider backdrop to all of this, and the likely basis for Mahmood’s decision, is that Britain is on tenterhooks after a spate of anti-Semitic attacks, including assaults against Jews in London and arson attacks on property.The most serious anti-Semitic attack in recent times was last year’s attack on a synagogue in Manchester, in which two Jewish worshippers died.The UK government has promised to tackle anti-Semitism by clamping down on divisive rhetoric. The refusal to allow entry to Uygur and Piker – even as both men insist they are not anti-Semitic, allows Mahmood to publicly telegraph those intentions to a wide audience.Another ramification, however, arrives in Britain’s declining reputation as a bastion of free speech. The Index on Censorship has responded by saying the British government has presided over a “worrying escalation” and is being too “paternalistic”.[ Britain's Jewish communities remain on high alert after Manchester attackOpens in new window ]