It was the celebrated historian A. J. P. Taylor who taught me a fundamental truth about my profession. Commenting more or less positively on a research seminar presentation I'd given, he remarked: "Remember, Geoffrey, that the historian's job is to destroy myth. Of course, it is far better to prevent myth in the first place."

It is in this spirit - prevention being better than cure - that I offer some thoughts triggered by the encomia that greeted the announcement that Lord Sacks is to retire as Chief Rabbi at his contractual retirement age in 2013.

No sooner had this news been broadcast than the accolades began their predictable fall from the predictable composers of shmaltz-laden, myth-ridden nonsense. But the top myth-making prize must go to the London Jewish News.

In its editorial of December 16, the JN made a number of astounding comments on Rabbi Sacks's career, as follows:

1) "He has called for a Judaism that unites everyone from Stamford Hill chasids to twice-a-year shulgoers."

Jewish News’s editorial insulted its readers' intelligence

It is certainly true that he began that way. In 1993, he published a book - One People? - which even I was constrained to describe as "a brilliantly written exposition" of the fault-lines separating Jew from Jew in the post-Holocaust world. To heal these divisions, Sacks urged the promotion of a Judaism that was inclusive rather than exclusive, and which spoke of other Jews in no language except "the language of love and respect."

What actually happened was that the retiring Chief Rabbi used the columns of the sectarian Jewish Tribune to launch a spite-laden attack on adherents of the Masorti movement, whom he publicly condemned for having "severed their links with the faith of their ancestors".

2) "He will surely be remembered as the Chief Rabbi who tackled religious diversity within our community more dynamically than any before him."

It is certainly true that he began that way. In January 1993, a fanfare of publicity attended the launch of Jewish Continuity, which even I was constrained to describe as "the most ambitious educational project ever undertaken by Anglo-Jewry."

What actually happened was that, two years later, Jewish Continuity was as dead as the dodo, its demise assured by its rabbinical chief's hasty retreat from the promise to fund projects irrespective of their precise denominational origins.

As soon as Jewish Continuity's "allocations board" began to approve non-Orthodox applications, there was uproar from the religious right. But instead of preaching "love and respect", Rabbi Sacks withdrew from the initiative, thus permitting his unfortunate brainchild to be swallowed up within the UJIA in 1997, specially created for the purpose of concealing a palpable defeat within a wholly spurious victory. Indeed it is difficult to disagree with Rabbi Shmuley Boteach who, last month in the Jerusalem Post, argued that, "with the notable exception of Limmud, which started as an independent, grassroots initiative, not a single new idea for Jewry has come out of Britain in the 20-plus years that Sacks has presided over it."

3) "He has striven to re-package Judaism as a faith that both embraces change and adapts to it, without ever compromising its fundamental truths."

It is certainly true that he began that way. As Chief Rabbi, he entered upon his ministry as a modernist, intent on promoting an Orthodoxy that embraced modernity as a divine gift. He even went so far as to publish a volume, The Dignity of Difference, in which he argued that Judaism - his Orthodox Judaism - did not have a monopoly of truth and could learn from other faiths. What actually happened was that, in order to placate the ultras, he rewrote the book and in so doing consigned as heresy dogma that he had previously promoted as orthodoxy.

4) "Lord Sacks has used his privileged position to unite the many flavours of our faith."

Really? The JN should try telling that to the family of Hugo Gryn, whom Sacks praised in public but delighted in excoriating in private. The JN should try telling that to the Sagal and Lightman families, whose children Sacks did his best to exclude from schools under his religious authority.

Every news outlet has a bias. But what the Jewish News has done is to voice a series of wild opinions that have no factual basis. Its December 16 editorial was not merely an insult to the intelligence of its readers. It was an affront to the media profession, a disservice to British Jewry and a piece of self-serving fiction that bears comparison with the preposterous narratives that emanate daily from the cheer-leading automatons of Pyongyang.