Edward Said once asked who, if not the writer, will "defeat the imposed silence and normalised quiet of power". Ghada Karmi is such a writer. Her book In Search of Fatima: a Palestinian story, to be published this month by Verso, is one of the finest, most eloquent and painfully honest memoirs of the Palestinian exile and displacement, which western power and its creature, Israel, have "normalised".

As a child in British Mandated Palestine, Ghada Karmi watched Jewish terrorists create the climate of fear and terror that gave Palestinian families the choice of fleeing or expulsion. She notes the irony that the word "terrorist" was invented by the British to describe the Jewish Irgun and the Stern Gang and its killers, two of whom became prime ministers of Israel.

Her family came as refugees to Britain, settling in, of all places, Jewish Golders Green. A few years ago, she looked for her home in Jerusalem and found in its place a kindergarten for religious Israelis. Everything of her childhood was gone, as if it had been airbrushed. "The scene could have come from the Orthodox Jewish part of Golders Green," she wrote. "Unutterably dismayed, I walked back and stood staring at what had been the site of our house. I squeezed my eyes shut to banish the present from my consciousness and recall the memories of childhood, the echoes of laughter and the scents and sounds which had been homely and familiar. But I could not. Flotsam and jetsam, I thought, that's how we ended up, not a stick or stone to mark our existence. No homeland, no reference point, only a fragile, displaced and misfit Arab family in England to take on those crucial roles."

The "quiet of power" is no more; the Palestinians, having fought back, are no longer alone. Last Saturday, up to 400,000 people filled much of central London calling for justice for them, and in opposition to the proposed criminal attack on Iraq. The two are linked; only the vintage of the imperial regime in Whitehall is different.

At the Israeli Ministry of Truth on Palestine, and its branches in America and this country, there is panic, which is understandable. Until recently, a Zionist narrative has dominated much of the region's historiography in the west; and Israel's immunity from truthful media criticism has been almost guaranteed. Tim Llewellyn, for many years the BBC's Middle East correspondent, has described this, accusing the BBC of "continuing to duck" its public service duty to explain "the true nature of the disaster [of the occupation] and Israel's overwhelming responsibility for it".

Merely to say that invites intimidation and smear, which, says Yishai Rosen-Zvi, one of the brave Israelis who have refused to serve in the Occupied Territories, "has been the huge bluff of the Israeli establishment. [Every] criticism of its policies is called anti-Semitism, [when] criticising your country's policy is the only patriotic thing that one can do." He said this in my documentary Palestine Is Still the Issue, which was broadcast on ITV1 last month.

The horde of mostly vicious, violent and threatening bigots who assaulted Carlton Television following the film's transmission made no mention of him or the other decent, reasoning Israelis I interviewed and featured. The wisdom and compassion of Rami Elhanan, a veteran of the Yom Kippur war, who lost his teenage daughter in a suicide bombing, were ignored.

He told me: "Someone who murders little girls is a criminal and should be punished. But if you think from the head and not from the guts and you look what made people do what they do, people that don't have hope, people who are desperate enough to commit suicide, you have to ask yourself, have you contributed in any way to this despair and craziness . . . the suicide bomber was a victim the same as my girl was . . . understanding is part of the way to solving the problem." Those like Rami and Yishai, wrote Miriam Karlin in a letter to the Guardian, "represent the best of Israel, humanity and true Judaism".

Indeed, most of those interviewed were Israelis, including "settlers" and Ariel Sharon's closest adviser, who was given the most airtime. Not a word about this was uttered by the ranters, who e-mailed their abuse and screamed down the phone from all points west of Finchley, including New York and California.

Many were Americans, none of whom had seen the film. Analysing the e-mails, we calculate that around 10 per cent are genuine critical responses to the film. Most of the rest have a generic theme, including those clearly orchestrated by a thoroughly sinister organisation called HonestReporting.

Following a similar assault last year on the Guardian's Middle East correspondent, Suzanne Goldenberg (who was abused as a "self-hating Jew"), an investigation by the paper revealed a website, www.honestreporting.com, that gave no address and was registered under a London name and phone number that seemed not to exist. The site was set up by a 27-year-old called Jonathan, who pleaded, as cowards in his situation do, that his name not be published.

This organisation is now funded in America by a front called Media Watch International, run by one Shraga Simmons. Simmons is employed by a group of Zionist fanatics known as Aish HaTorah. According to David Leigh in the Guardian, Aish HaTorah was "founded by Rabbi Noah Weinberg, who complains that '20,000 kids a year' are being lost to Judaism by marrying out. Aish invented speed-dating - eight-minute sessions in cafés to help New Yorkers find compatible Jewish partners. They're widely regarded as right-wing extremists. And they're certainly not entitled to harass the media into what they would call 'objectivity'."

It goes beyond that. Many of the e-mails are quite disgusting, containing menacing racist filth of the kind you associate with anti-Semitic fascists. The murder of my family is considered "not a bad idea". I am a "demonic psychopath" and likened to David Irving. Someone called Arie Karseboom says that I must belong to a Nazi party or have an Arab wife: otherwise, a film explaining the injustice done to the Palestinians is simply inexplicable!

The distinguished Israeli historian Ilan Pappe, whose works are taught in universities all over the world and who describes my film as "balanced [and] faultless in its historical description", is called a "pro-Arab dog" and worse.

In order to create the impression of an avalanche of complaints, many of the e-mails run to five or six pages. Not all the writers are American fanatics. At Carlton's offices in London, the duty officers have been abused by those close by. They have been called "worse than Hitler". I have had death threats. A Jewish friend says that the Jewish community has to take some responsibility for this outrageous behaviour from even its "respectable" members. For example, a doctor from Cheshire suggested in an e-mail that I had been personally bribed by Yasser Arafat in return for "programs like that [that] encourage the murder of innocent Jewish civilians . . ." Note the American spelling of programme, which indicates that the nice doctor from Cheshire may not write his own bile.

The invective and threats increased noticeably the day after Michael Green, the Jewish chairman of Carlton, attacked his own company's film in off-the-cuff abuse in the Jewish Chronicle, calling it "a tragedy for Israel" and "inaccurate". Two weeks on, Green has yet to identify let alone substantiate a single "inaccuracy". He should apologise to those of us who have distinguished his company with careful, fair and truthful work. His irresponsibility is a disgrace.

The Foreign Press Association in Jerusalem has complained to the Israeli government about its "defence force" targeting journalists - that is, shooting to kill them, just as they routinely kill Palestinians. The next step is for the same foreign journalists, who privately express understanding of the historic injustice done to people suffering one of the longest occupations in modern times, to reject the craven intimidation coming from New York and Finchley and Cheshire, and speak the truth.