In June 1983, shortly after she was re-elected to a second term by a landslide, Margaret Thatcher received a congratulatory letter from the Chief Rabbi.

Immanuel Jakobovits wrote to offer his “personal felicitations on the resounding endorsement of your resolute leadership”. He hoped, he continued, that she would “continue to guide the destinies of our country through these turbulent times on the firm foundations of our moral heritage which you have done so much to uphold and promote”.

Just over a year later, after the IRA’s attack on the Grand Hotel in Brighton, the Chief Rabbi wrote to Mrs Thatcher again. He expressed his gratitude at her “miraculous escape … at the hands of a merciful Providence”. The Prime Minister’s “personal example of fortitude” would be a “source of inspiration and great solace to the entire nation”.

His letters to Mrs Thatcher — who became Prime Minister for the first time 40 years ago this week — undoubtedly went beyond the somewhat rote wishes of congratulation and commiseration which normally flow between religious leaders and politicians.

And his affection and admiration were wholeheartedly reciprocated. Days after she moved into Downing Street in May 1979, Mrs Thatcher received her first visit from a foreign leader. With “her eyes ablaze with enthusiasm”, a member of Menachem Begin’s staff later recalled, the new Prime Minister began to sing the praises of “your marvellous Chief Rabbi here”.

He had, she continued, “an inspiring commitment to the old-fashioned virtues, like community self-help, individual responsibility, and personal accountability — all the things I deeply believe”.

Tellingly, she also drew a sharp contrast with “her” lily-livered bishops. “Oh, how I wish our own church leaders would take a leaf out of your Chief Rabbi’s book.”

The bond between Prime Minister and Chief Rabbi would grow throughout Mrs Thatcher’s 11 years in office. It was one that was centred on both a warm friendship and an ideological kinship. Stephen Sherbourne, who served as Mrs Thatcher’s political secretary during her second term, compared it to another of her special relationships: “She felt affinity with people who shared her approach to life and I think she felt that with Ronald Reagan. We are not talking politics here, we are talking about instinct and I think this is what she felt about Jakobovits.”

The pair had first met eight years previously when Mrs Thatcher was Education Secretary and Rabbi Jakobovits was embarking on his successful effort to improve the poor state of Jewish education.

“You are really the Minister of Defence,” he told her, underlining the importance he attached both to education and the role of schools in shoring up the nation’s moral foundations. With her love of martial-sounding and patriotic Christian hymns, it was an epithet which Mrs Thatcher both appreciated and remembered, recalling his words years later in Downing Street.

The Chief Rabbi’s gregarious wife, Amelie, attended to the social side of the budding friendship between her husband and Mrs Thatcher. The two couples dined together at the Jakobovits’ home in Hamilton Terrace and later in Downing Street.

On one occasion, Mrs Thatcher and Denis were dinner guests at the Chief Rabbis’ succah. As MP for Finchley, she was already a regular attender at community gatherings and functions. Nonetheless, Amelie recalled that both Mrs Thatcher and her husband were “always full of questions and wanted to know as much as they could from the Chief Rabbi about our rituals, the meaning of Jewish law, the meaning of Jewish ethics and the explanations”.

The Prime Minister and Rabbi Jakobovits also shared a deep interest in science, which was a frequent topic of discussion.

So close were they that she was one of the few people to address the Chief Rabbi by his first name.

Another such person was the Archbishop of Canterbury, Dr Robert Runcie. The Chief Rabbi and the head of the Church of England communicated regularly, often sending each other advance copies of their speeches. It was, therefore, no surprise in the autumn of 1985 when Dr Runcie sent Rabbi Jakobovits a copy of a report, ‘Faith in the City’, which the Church of England was about to publish. At 400 pages long, it was a devastating critique of the condition of urban Britain in general and the policies and political philosophy of the government in particular. Its publication sparked a huge political row that would draw the Prime Minister and Chief Rabbi still closer together.

A devout Christian and regular church-goer, Mrs Thatcher was angered and hurt by the report and what she viewed as its implication that her government cared little about the country’s cities and those who lived in them.

In private, she bemoaned the fact that it contained “nothing about self-help or doing anything for yourself”. In public, she bit her tongue, while newspapers carried reports of unnamed ministers denouncing it as “pure Marxist theology” produced by a “load of Communist clerics”.

Rabbi Jakobovits was similarly unimpressed. He felt, he later wrote, that the Church’s findings placed a great emphasis on the government’s shortcomings, while saying nothing about personal responsibility, the importance of “strengthening the family” and “the intrinsic value of work”. Perhaps most importantly, he believed that the solution to the plight of urban Britain “lies primarily in the efforts of the immigrants themselves”. The Chief Rabbi sent Dr Runcie a 20-page reply. The archbishop urged him to publish it in order to provoke a debate.

In January 1986, the JC cleared three pages to run “From Doom To Hope”, his lengthy dissection of the bishops’ attack on Thatcherism. Its power, and the resultant controversy, lay in the sharp contrast he drew between the manner in which Jews had worked their way out of the ghetto earlier in the century and life in Britain’s inner-cities in the 1980s.

His words were music to the Prime Minister’s ears. With the urban riots of 1981 and 1985 still fresh in his mind, Rabbi Jakobovits urged less talk about racism in the police force and more emphasis on the importance of teaching respect for law and order. Jews had not asked for “public help, nor changes in official policies” and had instead been prepared to “wait and struggle for several generations” to better themselves, he bluntly argued. He went on to provide some religious instruction on work, welfare and wealth-creation. The bishops, he suggested, had failed to recognise that work was “a virtue in itself” and that idleness was “a greater evil” than unemployment.

“No work is too menial to compromise human dignity and self-respect,” he claimed, and low-paid work was “more dignified than a free dole”. The Chief Rabbi went on to implicitly defend the Thatcher government’s emphasis on the importance of wealth-creation and charity and bemoan the “selfishness” of the unions and their “crippling” strikes.

Unsurprisingly, Mrs Thatcher was delighted by this defence. She felt, Mr Sherbourne believed, that “the record had been set straight”.

But there was something beyond pure politics which motivated the Prime Minister’s admiration for the Chief Rabbi.

While the Church of England seemed, she felt, embarrassed by its supposedly old-fashioned teachings, the Chief Rabbi evinced no such discomfort. She saw a man who, like herself, was willing to deliver hard truths — however unfashionable or unpopular.

Perhaps, too, she heard in the forthrightness and moral certainty of his teachings echoes of her beloved father, Alfred Roberts, a Methodist lay preacher with a similar respect for “Victorian values”.

The newspapers soon began to detect that, while relations with the Established Church were clearly strained, the Prime Minister had nothing but warm words for the “absolutely marvellous” Chief Rabbi who “always speaks up fearlessly on everything”.

For the Guardian columnist Hugo Young, Jakobovits was “private counsellor, supplier of spiritual uplift, therapist beyond the walls”. The Sunday Telegraph awarded him the accolade of “spiritual leader of Thatcherite Britain”. For the Daily Telegraph he was quite simply “the one prelate whose preaching did not, in the view of Mrs Thatcher, give God a bad name”.

The relationship was not one that was universally popular in the Jewish community. Jewish Labour politicians were predictably incensed by Rabbi Jakobovits’ attack on ‘Faith In the City’. Ian Mikardo branded it “absolutely disgraceful”, while Louise Ellman, then-leader of Lancashire county council, despaired at the Chief Rabbi’s attempt to “identify Jews and Judaism with the cruellest Conservative government since the war”.

Others in the community faulted Jakobovits’ reading of history and accused him of making it appear “self-congratulatory and self-righteous”.

Indeed, such was the outcry among some Jews — many of whom objected to the fact that his role appeared to have become politicised — that the Chief Rabbi felt moved to respond, saying he found those reactions “baffling and quite disturbing”.

As his close aide Shimon Cohen suggested, Rabbi Jakobovits was “not a political animal” and had not, perhaps, expected the Tories to leap on his words with such glee.

When, just over two years later, Mrs Thatcher offered him a peerage — the first Chief Rabbi to be so honoured — he made sure to seek the views of Labour peers and his friend Dr Runcie. All urged him to accept.

And certainly, Rabbi Jakobovits hardly proved a political stooge. His maiden speech attacked the government’s tightening of immigration controls. He would later bitterly attack its reforms to the NHS and cuts in health spending.

Shortly after her defenestration in November 1990, Mrs Thatcher delivered a speech to mark Lord Jakobovits’ retirement. The Chief Rabbi, she said, had had “a deep effect on me” and then wondered whether that made her “a Jakobovite or him a Thatcherite”.

In truth, it was simply a meeting of minds.

As Chaim Bermant wrote as her premiership entered its 10th year: “Their friendship arises not from the fact that one converted the other, but from a coincidence of attitudes, and she is sufficiently religious to cherish the fact that she has at least one man of God on her side.”

Robert Philpot is the author of ‘Margaret Thatcher The Honorary Jew: How Britain’s Jews Helped Shape The Iron Lady and Her Beliefs’