"You say you support the Palestinians?"

"Yes."

"Which Palestinians?"

"What do you mean 'which Palestinians'? I support all Palestinians. Their oppression by Israel is the great injustice of our time. Western hypocrites ignore racism, and use false accusations of antisemitism to stop legitimate criticism. The Zionist-controlled media label resistance 'terrorism', while ignoring the state terrorism of Israel which is the root cause of all the violence in the Middle-"

"All right, stop there. You still have to choose. Do you support the Fatah leadership in the West Bank, which may be corrupt and unpleasant but is at least presiding over an economic boom and allowing some freedoms, or Hamas, which tortures its enemies and tramples on the rights of women."

"Hamas won Gaza in free elections. Palestinians must unite against the colonial enemy and the Israel Lobby in the West."

"But they cannot unite. Religious reactionaries from the extreme right - and 'the extreme right' is the correct term, by the way - who are building an Islamic emirate in Gaza and want a caliphate to cover the whole world, do not mix with democratic politicians, however imperfect they may be. You saw what happened in Gaza. The Islamists won one election, cancelled all future elections, and threw their opponents from high-rise blocks. If David Cameron threw Ed Miliband off the Post Office Tower, would you still say that he was worthy of support?"

"It is not for us to intervene in Palestinian affairs. Hamas is an issue the Palestinians must resolve themselves."

"Listen to yourself. 'It's not for us to intervene?' You and your friends intervene all the time. You close down Jewish shops, oblivious to the ghosts of Kristallnacht that thuggish policy raises from the grave. You lobby to stop Israeli academics visiting our universities, and don't worry that the last movement to ban Jewish intellectuals was-"

"I knew it, I knew it! I knew you would accuse me of antisemitism. Your kind always does. It's a dirty trick to silence legitimate debate."

"I agree it can be sometimes. But when you will not condemn Islamist movements that lift Jewish conspiracy theories direct from the screeds of European fascism, I am entitled to suspect that you suffer from a severe case of Judeophobia at the very least. Your repeated references to the 'Israel Lobby' and 'Zionist-controlled media' don't reassure me on that score either."

"I am a left-winger, how dare you accuse me of racism? I have fought racism all my life, and don't ignore the Islamophobic racism of Israel and her friends, as you do. If there are antisemitic elements in the Islamist movement, they are a rational response to Western oppression. You would hate Jews if Israelis were doing this to you."

"Dear God, where to begin with that. Do you really believe there's no racism on the left, and that extremism can be rationally explained? In any case, it's not just antisemitism you excuse, is it? You have abandoned internationalism, secularism and, most disgracefully, the struggle for the emancipation of women. Your friends in Gaza have even banned women from sucking on hookah pipes - and, let me tell you, I don't need to have a psychiatry degree to understand the male sexual hysteria that lies behind that telling prohibition. Here's a test. The Palestinian Authority is about to declare the territories an independent state. The Israelis hate the idea, what do you think?"

"I worry that a two-state solution will not be full and just. The expelled refugees must have a right of return."

"That is a recipe for war without end. Israelis will never allow millions of Palestinians to swamp their state. Your trouble is that you are a voyeur. The violence of bearded reactionaries with a Koran in one hand and a Kalashnikov in the other excites you. You prefer their thrilling intransigence to the arguments of boring men in suits in Ramallah, who are willing to compromise for a better life. You need the burning corpses of Palestinians and Jews to bring light to your empty life."

"And your trouble is you are a sly apologist for imperialism. You never condemn Israeli atrocities, but use nit-picking points of detail and clever rhetorical tricks to distract attention from crimes against humanity. You are a neo-con and a zio-Nazi, and I am never going to speak to you again."

"Don't worry, there are millions more like you out there, and I'll be having this conversation for the rest of my life. Send in the next one on your way out."