British officials warned Prince William that it was not his role to act as a peace envoy between Israel and the Palestinians, a new book has revealed.

Foreign diplomats “immediately stepped in” after the Duke of Cambridge vowed to make it his “lifelong project” to resolve the conflict, following his landmark visit to the region in June.

The Duke is said to have “found himself being drawn into the complex politics of the region” after Israeli President Reuven Rivlin asked him to take a message of peace with him ahead of a meeting with Palestinian premier Mahmoud Abbas.

Royal expert and author Robert Jobson suggests in his new book, Charles At Seventy — published to coincide with the 70th birthday of the Prince of Wales on Wednesday — that the king-in-waiting’s “well-known public views on Islam and Arab friendships probably disqualified him from the role of peacemaker” on the first official royal visit to Israel and the West Bank earlier this summer.

He writes: “Charles’s Arab sympathies have led him to be accused of being anti-Jewish and anti-American.

“Perhaps that is one reason why it was his son William, not he, who was chosen by the Queen and Foreign to make the first historic visit.”

But while the Duke’s five-day Middle East trip, which included a visit to the Kotel and the West Bank refugee camp of Jalazone, attracted a multitude of glowing headlines about his deft diplomatic skills, the new book makes clear that British diplomats acted fast to ensure the royal visitor did not become too entrenched in the complex dispute.

“Inevitably, he found himself being drawn into the complex politics of the region and asked to act as a peace envoy when Israel’s president asked him to take a message of hope to the Palestinian premier,” writes respected royal author Mr Jobson, who has met and spoken with Charles on numerous occasions.

“British officials immediately stepped in and insisted that was not William’s role.”

Instead it was hoped that the trip would act as something of catalyst “to kickstart a long-stalled peace process in the world’s most intractable dispute”.

The book, which draws on the knowledge and memories of a number of sources who have never previously spoken, also provides an analysis of Prince Charles’ own views on the region — detailing a succession of pro-Arab statements he has made, but crucially stating neither “his intention or his position” to be in any way viewed as “anti-Jewish”.

But what Charles genuinely believes is that a resolution to the Israel-Palestine issue is the only means of achieving wider peace across the Middle East and with the West.

The book says: “In the prince’s view the only way proper democracy will ever be achieved in Iraq… is by dealing with the ‘real toxin’ infecting the whole world — the Israel-Palestine question.

“He maintains that the West must focus on education and resisting what he believes is a ‘terrible distortion’ of Islam and how it is perceived.

“Only then — when the wider world embraces the real Islam, combined with a serious collaborative effort to find a workable solution to the Israel-Palestine question — will, in the Prince’s opinion, the rage that drives the war on terror start to wane. The lack of a realistic and satisfactory solution to the Israel-Palestine problem, in his view, is the fundamental reason for hostility and all the ‘pent-up poison’ throughout the Islamic world.”

A close source quoted in the book states: “I have heard him (Charles) say time and again, ‘Remove the poison and you remove the cause of so much of the terrorism.’ The source added this is “the prince’s core belief on the issue”.

Rejecting suggestions of anti-Jewish bias in Charles’ beliefs, the book suggests; “This is certainly not his intention or his position. However, to this day he strongly believes a solution can be achieved only by listening to and acting upon the advice of powerful Muslim figures.”

The book recognises how Charles was widely criticised after a letter he wrote to his friend Laurens van der Post in 1986 was made public last November.

It became apparent that the prince had blamed what he described as the “influx of foreign Jews” for unrest in the Middle East. He also suggested the US should “take on the Jewish lobby”.

The letter, which was found in the public archive, had been written after a visit to Saudi Arabia, Bahrain and Qatar, with his then wife Princess Diana.

In his book, Mr Jobson, a royal commentator for the BBC, ITV and Australia’s Channel 7 channels, suggests Clarence House “rather lamely” said the opinions had not been Charles’ own views and were in fact the views of others. But the new book states: “It certainly didn’t read like that.”

Another reccurring theme is Charles’s lack of trust in American opinion. He is said to have found it “absolutely extraordinary” that neither the British, under Prime Minister Tony Blair, or America, under George Bush, had listened to the Arab perspective ahead of the 2003 invasion of Iraq.

He blamed this “dismissive unwillingness” to listen for the rise of militant Shia Islam under the influence of Grand Ayatollah Sistani.

Prince Charles celebrated his 70th birthday on Wednesday with a tea party with charity volunteers at St James’s Palace before heading off for dinner at Spencer House.

In a tribute written for the occasion, Chief Rabbi Ephraim Mirvis described the Prince of Wales as an ‘ohev Yisrael’ — a true friend of the Jewish people.

'Charles at Seventy: Thoughts Hopes and Dreams' by Robert Jobson (John Blake £20) is out now