Respect MP George Galloway walked out of an Oxford University debate after discovering a fellow panellist was Israeli.
Mr Galloway was on a panel alongside Eylon Aslan-Levy on Wednesday night discussing whether Israel should pull out of the West Bank.
The Bradford West MP had initially spoken for around 10 minutes in favour of a motion supporting immediate Israeli withdrawal.
Mr Aslan-Levy then spoke in favour of Israel, saying: “We wanted peace, we got war, we must not make the same mistake again.”
Mr Galloway interrupted: “You said ‘we’, are you an Israeli? I don’t debate with Israelis, I’ve been misled, sorry. I don’t recognise Israel and I don’t debate with Israel.”
He then walked out.
Later the MP tweeted: “I don't debate with Israelis or speak to their media. If Israelis want to speak about Palestine they can talk to the PLO.
“Israel: simple, No recognition. No normalisation. Just Boycott, divestment, sanctions. Like Apartheid SA. No Apartheid in Israel-Palestine.”
Mr Aslan-Levy said: "I am appalled that an MP would storm out of a debate with me for no reason other than my heritage. To refuse to talk to someone just because of their nationality is totally unacceptable for a Member of Parliament."
Mr Aslan-Levy, from Finchley, north London, is a former JC On Campus columnist. He wrote a series of articles about Jewish student life at Oxford two years.
Commenting on the incident, and yesterday's protests against Israeli deputy ambassador Alon Roth-Snir at Essex University, Board of Deputies vice-president Jonathan Arkush said: "All right minded people should condemn these acts against free speech and all universities should take steps to ensure that people are safe and secure to visit our campuses, irrespective of their race, faith or nationality."