Originally published in The Express
Last October Mr Corbyn, who is favourite to win the Labour leadership when the results are announced on Saturday, was one of the signatories of a letter defending the activities of the charity Cage.
It hit the headlines in March after its leader Asim Qureshi described Mohammed Emwazi, known as Jihadi John, as a “beautiful young man”.
The charity has a long history of supporting extremists, including radical Muslim cleric Abu Hamza and Aafia Siddiqui, dubbed “Lady Al Qaeda”.
Robin Simcox, research fellow at the Henry Jackson Society, an anti-extremism think tank, said: “Cage is a hugely problematic organisation and has been for some years. They are involved with and have backed various convicted terrorists.
“They are involved with people like Al Qaeda cleric Anwar Al Awlaki and have a host of other undesirable associations.
“It is an organisation that any politician should think carefully about before allying themselves with it.”