A vocalist whose songs contain lyrics such as “all the Jews will pay” and “we throw stones, small and big, at the Jewish demons” withdrew from a concert at an Islamic festival at London’s Excel Centre after the JC exposed him.

Abdel Fattah Owainat, a Jordanian vocalist who has posted footage of terror attacks and training over a soundtrack of one of his own songs glorifying violence after October 7, cancelled his appearance at the Global Peace and Unity (GPU) festival on Shabbat.

But the presence of a number of controversial speakers at the festival – which has attracted audiences of 55,000 and is the largest of its kind in Europe – prompted concern among security experts and community leaders.

The two-day festival last weekend featured speakers who have backed Hamas. A “River to the Sea” children’s colouring book was for sale at a stall. In a breakout event during the festival, a rapper and songwriter performed a song about the Middle East conflict in which he sang: “You blame me for defending myself / Against the ways of my enemies / Terrorising my own land / And I’m the terrorist?”

The Jewish Leadership Council (JLC) and Community Security Trust (CST) called for greater oversight, while the Campaign Against Antisemitism branded the event “outrageous”.

The Metropolitan Police’s logo was included on GPU material as a “supporting partner” of the festival. Last week the force had it removed after a complaint by the Policy Exchange think-tank. However, a spokesman for the Met told the JC that they had never given “formal permission” for the logo to be used.

Lord Carlile, the former reviewer of government terror legislation, condemned the festival, demanding greater care and scrutiny from both the Excel Centre and the Metropolitan Police to ensure that platforms are not given to extremists.

“It is very important to be extremely careful not to support or give a platform to those who support Hamas or any other such extremist behaviour,” he said.

The list of speakers at the festival included Professor Ilan Pappé, an academic at Exeter University known for his radical anti-Zionism, and activist Ismail Patel, who has met Hamas leaders in Gaza and “saluted” the group for “standing up to Israel”.

Also listed was the social media theologian and self-proclaimed “race realist” Paul Williams, who has a million followers across X/Twitter and YouTube. He was due to deliver a speech on Sunday.

Williams has hailed an interview with former BNP leader Nick Griffin entitled “Jews, Zionism, the far-Right and Islam in Europe” as “superb” and shared a video by the American white supremacist Jared Taylor about the “biological reality of race”.

The former far-right Dutch politician Joram van Klaveren, who sensationally converted to Islam in 2018 and has since shared a video denying that mass murder and rape took place on October 7, was also due to speak.

In addition, the festival platformed a number of provocative American speakers. One of these, Medea Benjamin, is the co-founder of the radical activist group CodePink. On the day of the October 7 Hamas attacks, Benjamin tweeted: “The Israeli government can’t keep two million trapped in an open- air prison in Gaza and not expect resistance.”

Following the assassination of Hamas leader Ismail Haniyeh, she referred to the “murder” of Hamas’ “key negotiator”.

Russell Langer, JLC Director of Public Affairs, said: “It is ironic that a conference purporting to promote peace and unity felt the need to warn their speakers and attendees not to show support for a terrorist organisation responsible for the worst attack against Jewish people since the Holocaust.

“This case should serve as a reminder to venues and respectable speakers to undertake due diligence in order to ensure they are not associated with anybody who has expressed antisemitic views or support for terrorism and violence.”

A CST spokesman said: “It is essential that the organisers of conferences such as this ensure that they do not provide a platform to anybody who has expressed antisemitic views or support for terrorism and violence, or who is likely to do so at this event.

“All respectable, mainstream organisations connected to this event, including the venue itself, ought to review their procedures to ensure that similar mistakes cannot be made in future.”

In 2020, Owainat, whose music features on a compilation album called Jihadi Hills, was accused of performing traditional songs “in the name of” Hamas in an academic paper published by Edinburgh University Press. A video showing rockets being launched by militants was accompanied by his lyrics: “Strike, may my father and mother be sacrificed for you, oh fire, make the enemies drink humiliation… The lands are forbidden to enemies… Allah is the greatest, proclaim it, all the Jews will pay.”

Another of his lyrics runs: “Know me, O Son of Zion: no matter how strong you are, for my country, blood is cheap… We throw stones, small and big, at the Jewish demons.”

A Board of Deputies spokesman said: “We would urge that the Metropolitan Police, who we understand to have been in attendance, urgently investigate the claims made against this singer and that festival organisers apologise for his invitation.”

In response to the JC’s disclosures, the Met pledged to scrutinise the event. “We’ve passed the material you provided to officers for further assessment,” a spokesman said. “We will of course take steps to assess whether any offences have taken place.”

Two Labour politicians, Naz Shah and Stephen Timms, were been billed to speak at the festival. Timms, the MP for East Ham, pulled out last week after reports that one of the speakers, the grandson of Nelson Mandela, was an “outspoken supporter of Hamas”. Naz Shah MP did not reply to the JC’s request for comment.

Since its inception in 2005, GPU conferences have been dogged by accusations of extremism. Past speakers include the cleric Zakir Naik, who was later banned from entering the UK, and CAGE activist Moazzam Begg.

The Muslim Council of Britain (MCB) is listed as a “supporting partner” of the event. In the 2010s, the then-Labour government cut off all dialogue with the MCB because of its alleged links to extremism. Successive governments, including the current one, have continued this policy of non-engagement.

Lord Carlile, the government’s former terrorism expert, said: “It is astonishing that the owners of Excel did not carry out due diligence as to who will speak at the event. One thing to examine is whether a duty should be imposed on the owners of venues, comparable with the new Martin’s Law, to require them to undertake due diligence so that people who support those who commit terror acts, such as Hamas, are not allowed to speak.”

He added: “So far as the police are concerned, they took their name off publicity for the event. But I remain very concerned that they were ever supporting the event in the first place.”

Ahead of the event, GPU organisers have warned to participants not to voice support for banned groups such as Hamas, the Telegraph reported.

A spokesperson for the CAA said: “This conference is outrageous. From celebrating the deadliest massacre of Jews since the Holocaust, to denying the horrors of that barbaric day, to alleged affiliations with the very group that carried out these atrocities, the speakers and performers at this event appear to tick every box of extremism. It beggars belief that the Met was a partner to this event.”

When approached for comment, Owainat denied all allegations of extremism.

Paul Williams, Joram van Klaveren, Ilan Pappé, Ismail Patel, Medea Benjamin, GPU and the Excel Centre have been asked for comment.