Conservative MP Crispin Blunt, chairman of the Foreign Affairs Select Committee, has appeared alongside a campaigner who supported the blood libel cleric Raed Salah.
A fringe session at the Conservative Party conference in Birmingham on Tuesday featured Mr Blunt speaking on a panel with Ismail Patel, chairman of the Leicester-based Friends of Al-Aqsa group.
Mr Patel was a leading supporter of Sheikh Salah when the Palestinian cleric successfully defeated Theresa May's attempt as Home Secretary to deport him from Britain in 2012.
He also travelled on the Mavi Marmara boat which was part of a flotilla which attempted to reach Gaza in 2010. Activists on the ship clashed with the Israeli navy and nine Turkish citizens were killed.
In January the Co-operative Bank closed the Friends of Al-Aqsa's bank account.
This summer it was reported that Friends of Al-Aqsa had attempted to make a five-figure donation last year to Jeremy Corbyn's Labour leadership campaign, although the cheque was not cashed.
Tuesday's session, organised by Mr Patel's group, focused on whether British aid to the Palestinian territories was a "help or hindrance to justice".
Mark Gardner, Community Security Trust communications director, said: "This meeting is somewhat ironic and surprising, given Ismail Patel's support for the infamous Raed Salah."
Lord Palmer, Liberal Democrat Friends of Israel president, added: "I am disappointed that any political party thought this was a man whose views we want to hear. Did his co-panellists and the meeting chair disassociate themselves from his past support for Raed Salah?"
Mr Blunt - seen as a senior Commons figure thanks to his select committee role - did not respond to requests for a comment about his appearance alongside Mr Patel.
The Tory MP is a former chair of the Council for the Advancement of Arab-British Understanding and is regarded as a long-standing supporter of the Palestinian cause.
He was criticised in 1999 after telling the House of Commons he believed "a Holocaust of equal proportions has happened to the people of Palestine who have been evicted from their homes and suffered disruption to their lives". Mr Blunt later wrote to the JC to apologise for offence caused by the remark.
Tuesday's discussion was held in one of the dozen venues hosting Tory conference-related events but was not booked through the party itself. The JC understands the Conservatives regarded it as an independent event run by an independent organisation.
Jeremy Corbyn has been widely criticised for his support of Sheikh Salah.
The Labour leader told a Commons committee in July that he had tea with the cleric during his visit to London in 2011 because the sheikh was under house arrest.
Mrs May's efforts to deport Sheikh Salah were seen as a key strand of her work at the Home Office during the nine-month campaign in 2011 and 2012.
Senior judges ruled that he was free to remain in Britain, despite having given a sermon in 2007 in which he invoked the blood libel.
After that ruling, Mr Patel said the court decision was a "victory for those who believe in freedom of speech and who support the Palestinian struggle for freedom from occupation".
Mr Blunt responded to our requests for a comment after we went to press. You can read his response here.