"Let us all agree on one thing at least. The more Jews warn that anti-Semitism has come roaring out of the closet, the more people don't like the Jews. Which is a bit of a problem if you believe, as I do, that the oldest hatred has indeed alarmingly resurfaced but is hiding under the respectable skirts of hostility to Israel.
This week, the European Union finally admitted there was a problem with rising Jew-hatred. While there was no comparison with the Holocaust, said European Commission President Romano Prodi, some criticism of Israel was 'inspired by what amounts to anti-Semitic sentiments and prejudice'. Yesterday, the Community Security Trust, a Jewish charity, reported the second largest rise in 20 years in attacks on synagogues, cemeteries and Jewish people in Britain.

Yet there were immediate moans in the press of 'grossly exaggerated' warnings about rising anti-Semitism. In an Economist debate at London's Institute of Contemporary Arts last week, those issuing such warnings were accused of being the 'new McCarthyites', waving the shroud of the Holocaust to stifle legitimate criticism of Israel.

So when a woman said to me one evening, 'I hate the Jews', I should have dismissed my shock as a 'grossly exaggerated' response. When I was listed in a newspaper as one of the Jews exercising sinister control over public debate in Britain, I should have said I brought this on myself by writing anything at all.

When I heard claims by a radio reporter that the Jews might have 'poisoned the water wells of Egypt' in 1947, I should not have wondered why one of the stock libels of medieval Jew-hatred was being broadcast as if it were true, since my concern was obviously shroud-waving.

And when in the ICA debate Tory MP Robert Jackson accused British Jews of dual loyalty, saying their Britishness was conditional on their explicit repudiation of the policies of Sharon, it was obvious the reason he was singling out the Jews as second-class citizens in this startling way was because they are McCarthyites.

Let's all agree on something else. Some Jews grossly over-react to perceived anti-Semitic bias. Their campaign of insults is as bad as the kind of insults which wing their way with monotonous regularity to me.

Nevertheless, as Chief Rabbi Jonathan Sacks told the EU conference, an unholy alliance between the Left, the far-Right and the Islamic street means millions are being told that alone among nations, Israel has no right to exist and that all the troubles of the world are the work of the Jews.

At the heart of this bitter disagreement is the conflation of the issue of Israel with the issue of Jew-hatred. The latter claim maddens people who feel they can't criticise Israel without risking being accused of anti-Jewish prejudice. The two, they say, are not connected. In theory, that's true. In practice, one issue often morphs into the other, both implicitly in the way Israel is described and explicitly in overt Jew-hatred.

Criticism of Israel is certainly legitimate, as is criticism of any country. I am myself critical of its policies. But a line has been crossed into something else - the demonisation and dehumanisation of Israel based on systematic lies, libels and distortions. As a result, a lot of decent people have been unwittingly caught up in a narrative of hatred.

Former Sunday Times editor Sir Harold Evans tried to show where that line should be drawn. It was not anti-Semitic, he said, to report Israeli ill-treatment of Palestinians or Sharon's past, or to deplore the long occupation of the territories. It was anti-Semitic to present Israel as diabolical, to invent malignant outrages, to condemn actions by Israel while not condemning worse elsewhere, and to vilify Jews so as to incite violence.

In all four categories, that line has been crossed. Diabolical? Israel is routinely described falsely as an apartheid or, worse, Nazi state. While its society is far from perfect, Arab Israelis not only have the vote but serve in the Knesset, supreme court and army. To label it 'Nazi' is to delegitimise it.

Malevolent outrages? Look at the so-called 'massacre' of Jenin, which has become an accepted fact even though there was no massacre: 23 Israeli soldiers and 52 mostly armed Palestinians died in that incident. There are some appalling and inexcusable incidents in Israel. But that doesn't explain why Israeli self-defence is systematically and falsely represented as malevolent aggression.

Double standards? British academics try to impose boycotts on Israeli universities. Yet they organised no boycotts against Kuwait, which expelled 350,000 Palestinians in 1991; or Jordan, which murdered tens of thousands of Palestinians; or Syria, which has occupied Lebanon. And increasingly, people are saying Israel should not exist at all, thus singling it out alone for destruction.

Inciting violence? People such as Lib Dem MP Jenny Tonge have come close to excusing the mass murder of Israelis in a manner they would never apply to the mass murder of other peoples.

Coverage of Israel is obsessive and disproportionate, and marked by a hysteria and malice not applied to any other conflict. And it cannot be divorced from the overt Jew-hatred that has now surfaced in Britain and Europe, particularly the give-away calumny of world Jewish power. The claim that Jews conspire to dominate the world is one of the oldest tropes of classic Jew-hatred. Astonishingly, claims made by the European Left are not far removed. It repeats claims that the 'powerful Jewish lobby' is now running American foreign policy. When Labour MP Tam Dalyell observed that a 'cabal' of Jewish power was behind Blair, he was thought a loveable eccentric. In the House of Lords, a meeting heard that Jews control the British media. One peer told a Jewish colleague: 'We've finished off Saddam. Your lot are next.'

The outcome is that an astonishing axis has developed between Islamic Jew-haters and the Left, marching behind the banners of 'human rights' on demonstrations in Europe producing chants of 'Hamas, Hamas, all Jews to the gas'.

Why? The main reason is ignorance of both the Middle East's history and its present. Next, the Left's hatred of Sharon is so great, along with its prejudice that America/the West is the oppressor and therefore the Islamic/Third World the victim, that it can't see what is happening.

Then there's the Left's deconstruction of the very concepts of objectivity and truth, so that it has become a conduit instead for propaganda and lies; and finally, its own history of Jew-hatred from Marx onwards. The final twist is that there are some Jews on the Left who subscribe to all the above too.

Former Archbishop Desmond Tutu said people were scared to say the Jewish lobby in America was powerful. So what? he asked. 'The apartheid government was very powerful but today it no longer exists. Hitler, Mussolini, Stalin, Pinochet, Milosevic and Idi Amin were all powerful, but in the end they bit the dust.'

So Jews not only have vast power, according to Tutu, but are on a par with those tyrants. Yet it was Tutu who could publish this calumny about the Jewish people, and thus incite yet more to hate them. But of course, any Jews who call this by its proper name are the new McCarthyites."

· Melanie Phillips is a Daily Mail columnist