Former vicar Stephen Sizer, who once supported claims that Israel was behind the 9/11 terror attacks, will no longer speak at Momentum’s Gaza fundraising dinner in London next month, after the left-wing grassroots group behind it withdrew the invitation.

Rev. Stephen Sizer was due to speak at the Star of India restaurant in Leytonstone on 3 October, for a charity dinner hosted by Ilford Momentum.

However, a spokesman for Ilford Momentum apologised on Thursday, saying the organisers had not known about Sizer’s past comments, which have been described by the Bishop of Guildford as “appalling” and “antisemitic”.

Dr Sizer, who is notoriously anti-Israel, courted controversy for participating in a 2014 conference in Iran, which was described as a “anti-Semitic hate fest”. He has also spoken several times on Iran’s Press TV and lectured in the country.

In 2012, Rev Sizer, a leading voice in the UK for replacement theology, had caused controversy by posting a Facebook link to an article on an anti-Semitic, Holocaust-denying website.

Coming to Sizer’s defence in 2012 was the now Labour leader, Jeremy Corbyn, who wrote to the Church of England saying that Sizer “seems to have come under attack by certain individuals intent on discrediting the excellent work that Stephen does in highlighting the injustices of the Palestinian Israeli situation, in particular by his very thorough analysis of ‘Christian Zionism’.” Corbyn continued, “Might I suggest that such criticism is part of a wider pattern of demonising those who dare to stand up and speak out against Zionism, a philosophy that precludes the existence of the state of Palestine?”

Corbyn then went on to blame the internet for Sizer’s antisemitic post, saying,  “The internet is a complicated piece of technology and with the best will in the world, imperfect links are made and one would have to spend 8 hours a day “surfing” the net just to be 100% certain one’s views to not become contaminated in any way at all. Even then, connections can inadvertently be made.”

In December 2015, the Church of England condemned Sizer for sharing material which was “clearly antisemitic”. Sizer agreed not to write, speak or tweet about the Middle East for six months after he was disciplined for posting a link to an article suggesting Israel carried out the 9/11 attacks.

Sizer, who lectures in Iran, also defended his appearance in the 2014 New Horizon conference held in Tehran, which included sessions such as “Zionist Fingerprints on the 9/11 Cover-up” and has met Hezbollah’s leadership and toured south Lebanon with the terror group. He has given interviews on Iran’s Press TV, including one in which he said the Holocaust has been “perpetuated” for the past 40-50 years and that it is the Palestinians now experiencing a Holocaust.

Stephen Sizer meets Nabil Kaouk, a top Hezbollah official and militant commander, in Lebanon

Despite resigning from his post at Christ Church in Virginia Water, Surrey, in 2016, Sizer remains a prolific opponent of Israel and advocate of replacement theology through his new organisation, Peacemaker Trust. Whilst in Australia, broadcaster ABC came under fire for interviewing Sizer on breakfast TV on the morning of Passover in which he claimed Zionists have “diluted the definition of anti-Semitism to include criticism of Israel”.