Mandy clashes with Bibi in a London square

The Middle East came to Trafalgar Square on the bank holiday Monday. The pigeons were displaced from their homeland by the largest rally of Anglo-Jews ever - more than 40,000 turned out. And at the far corner of the square, by the Mall, a core of Palestinian supporters was fenced in by the police.

Several people in the crowd remarked that central London had become a microcosm of Israel/Palestine. The omnipresent threat of suicide bombings have made large public gatherings almost impossible there - yet, here in London, the two sides could still stand face to face.

The Palestinian crowd was overwhelmingly young, male and soaked in testosterone. Women were largely silent before the fist-clenching men. Across Trafalgar Square, on the steps of St Martin-in-the Fields church, Jews for Justice staged a peace vigil with banners announcing: "We are ashamed to be Israeli today". This 500-strong group received the greatest abuse from the pro-Israel crowd. "Why don't you go and join Hamas, you f***ing scum?" one woman called. Yet even the rest of the Israeli crowd, which seemed homogeneous at first, were separated along clear dividing lines. Peter Mandelson delivered an extraordinary, barnstorming speech that (I never thought I'd write this) eloquently expressed the views of the left - or the Israeli left, at least.

Mandelson, while expressing strong support for Israel's existence, drew on his experience of Northern Ireland to oppose a military solution. "Politics, not violence, secures people's lives," he yelled, his voice almost cracking. "You will only get peace by pursuing a political route . . . Security for one can only come when there is security for all." At a time when Israel is ruled by a man who opposed the Oslo model of dialogue with the Palestinians from the beginning, it was a controversial message, an attempt to appeal to the Jewish diaspora over the heads of belligerent Israeli politicians.

This became apparent when Binyamin Netanyahu, the former (and probably future) prime minister of Israel, took the stage. Netanyahu did not deliver a rallying call for Israel but for Likud, his own hard-right party. Netanyahu raved against the Palestinians. He said that opposing the PLO was the moral equivalent of opposing Hitler. Those who seek dialogue (like Mandelson) have merely fallen for "the sophistry of the apologists for terror". Arafat was "feeding children into the fire - and serious people, serious statesmen, want to give this man a state?".

"This isn't supposed to be a political event," called out one woman. "He's trying to hijack it." But it was too late. The cheers for Netanyahu were even more deafening than those for Mandelson. More than one liberal Jew left in tears.