What Menzies really thought of the Commonwealth

The documents show he openly questioned the Commonwealth's viability and accused new member nations of thriving on antagonism, by waging a coordinated campaign of anti-colonialism engineered to strip "White men" of their power.

Kirsty Johansen with this report by Brett Mason.

The personal and private telegrams exchanged by Prime Minister Sir Robert Menzies and British Prime Minister Harold Macmillan were so sensitive, the Secretary of the Cabinet at the time warned they should not be read by anyone at all in the civil service.

Bureaucrats in Canberra were even instructed to further limit their circulation.

In the letters from 1962, Sir Robert Menzies confessed to his British counterpart his enthusiasm for the new Commonwealth was wearing thin.

He wrote, "people like me are too deeply royalist at heart to live comfortably in a nest of republics and the new republics seem to thrive on antagonism."

He also revealed his reluctance to travel to London for a Commonwealth Prime Minister's meeting, complaining about his uncomfortably close 1961 election victory.

In a reply, the last British Prime Minister born during Queen Victoria's rule and to have fought in World War I, painted a very different picture of the world.

Prime Minister Macmillan said he, too, believed the Commonwealth had become what he called "an absolute tragedy", with young and inexperienced nations itching to interfere.

Juliette Desplat is the head of Modern Overseas, Intelligence and Security Records at the British National Archives.

She says the letters really give an insight into the political pressures of the era.

"I thought the letter was really fascinating because obviously it was a private letter and it's sent privately from Macmillan to Menzies and he's talking to him as if talking to an old friend, which they probably were."

Sir Robert Menzies also vented his fury at plans to discuss increased movement of populations between Commonwealth countries, at the upcoming summit.

He wrote:

"If we were at liberty to discuss the internal racial policies of one member, it would be quite legitimate that at some subsequent meeting to discuss, for example, the Australian immigration policy which is aimed at avoiding internal racial problems by the expedient of keeping coloured immigrants out."

It reiterated Sir Robert's thoughts on the White Australia policy, which he discussed with radio 2UE's Stewart Lamb in 1955.

"I don't want to see reproduced in Australia the kind of problem they have in South Africa or in America or increasingly in Great Britain. I think it's been a very good policy and it's been of great value to us and most of the criticism of it that I've ever heard doesn't come from these oriental countries it comes from wandering Australians."

(Lamb) "For these years of course in the past Sir Robert you have been described as a racist."

(Menzies) "Have I?"

(Lamb) "I have read this, yes."

(Menzies) "Well if I were not described as a racist I'd be the only public man who hasn't been."

In his reply to Sir Robert's 1962 letter, Prime Minister Macmillan also mulled over the end of "white" dominance, offering a unique insight into the pressures of high office.

He wrote: "What the two wars did was destroy the prestige of the white people."

He went on to say, "What we have really seen since the war is the revolt of the yellows and blacks from the automatic leadership and control of the whites."

Ms Desplat says the section went on for 18 pages.

She says they're staggering personal reflections from a Prime Minister who so publicly embraced decolonisation.

"He rambles on, if I may say, for 18 pages. On 18 pages he explains the state of the world, the state of the Commonwealth, the changes in the world due to the Cold War and the ideological war that is being waged. So a really fascinating tone because it's so personal and it's really something that was probably not meant to be seen."

In the letters, Sir Robert Menzies joined forces with former President of the United States John F. Kennedy to personally encourage the United Kingdom to join the European Economic Community, now known as the modern European Union.

During a meeting in Washington, he claimed Mr Kennedy said to him, if Great Britain goes into the European community, both countries would have a lively interest in maintaining and developing their own trade into the extended Europe and avoid over-nationalistic economic policies in the bloc itself.