A week before Jeremy Corbyn was elected leader of the Labour party, the Daily Telegraph published an editorial warning the party was set become "a Trojan Horse for the naïve and reckless". Ironically, that is exactly what the Telegraph has become – a Trojan Horse for the propaganda of autocratic foreign powers. The once newspaper-of-repute has quietly offered its services to various human rights abusing regimes including the Chinese Communist party, Vladimir Putin, and the brutal autocracies of the Sunni Gulf states.

Last month, Private Eye reported that the proprietors of The Telegraph, the so-called Barclay brothers, had renewed their contract to publish a supplement from China Daily – the propaganda mouthpiece of the Chinese Communist Party. China Watch brings Telegraph readers "informative and diverse stories about contemporary China's dynamic development.” There is certainly a great deal of positive news to report from China, but as has been widely discussed of late executions, torture, detention without trial and even alleged organ harvesting by the state remain systemic. While the Spectator, Daily Mail and the Times all reported this during the recent state visit, the Telegraph was obsequious. "President Xi should rest assured that he is a welcome guest in our country," their editorial fawned. Speaker John Bercow, who bravely spoke out, was accused by the editors of political "grandstanding".

Talking of postures, take The Telegraph's equally submissive stance towards the Kremlin. Their monthly supplement - “Russia Beyond the Headlines” isn't an incisive investigative look at Putinist corruption, nor a crack team of undercover reporters exposing the Kremlin-funded far-right gangs supported by Putin.

Beyond the Headlines is another soft power extension by a Russian state-owned newspaper, Rossiyskaya Gazeta. It publishes seemingly innocuous articles about Russian culture, carefully designed to improve Russia's reputation in the West. The Telegraph, pimped out by the Barclay brothers to Kremlin propagandists, is thought to receive at least £40,000 per month for the arrangement.

Yesterday, The Telegraph published what amounts to a blackmail threat from Mohammed bin Nawaf bin Abdulaziz, Saudi ambassador to London. Offered an uncontested platform, the diplomat essentially threatened to withdraw warnings of deadly terrorist attacks unless the UK media shut up about the crucifixions his family members are planning, or the alleged war crimes they are committing in Yemen.

It is important to see this threat in context. In 2008, another Saudi royal, Prince Bandar, suggested "another 7/7" might be in the offing, unless the Serious Fraud Office called off an investigation into corrupt arms deals implicating several Saudi princes. Far from a security partner, the Saudi princes are literally prepared to sacrifice British lives, Telegraph readers included, for their own personal gain.

It would have been appropriate for the Telegraph to either print a concurrent editorial calling out Abdulaziz for blackmailing the UK or a news piece reporting on his threats, while giving space for security analysts and human rights activists to explain how menacing this message really was. Instead his murderous threat went unchallenged.

Whether you like or loathe the paper's Tory partisanship, platforming dictators makes Jeremy Corbyn's brief meetings with Hamas look like a squall in a tea cup. It's an unprecedented shift for a once-great paper.