Palace letters show Queen did not order 1975 removal of Australian Prime Minister Gough Whitlam

Queen Elizabeth II was not forewarned of the 1975 removal of Australian Prime Minister Gough Whitlam by then Governor-General John Kerr, according to classified papers released Tuesday, which reveal new details about the country's biggest constitutional crisis.

Letters between Kerr and Buckingham Palace were made public after a years-long court battle, but ultimately did not contain the smoking gun that some observers had expected -- that the Queen had directly ordered Whitlam's removal.

Kerr, who died in 1991, said he took the decision on his own, only later informing the Queen, because "it was better for (her) not to know."

"I decided to take the step I took without informing the Palace in advance because under the Constitution the responsibility is mine and I was of the opinion that it was better for Her Majesty not to know in advance, though it is, of course, my duty to tell her immediately," Kerr wrote, according to the documents.

After Whitlam's minority Labor government struggled to pass legislation amid intense opposition, Kerr stepped in to remove him as prime minister, appointing Liberal Party head Malcolm Fraser as caretaker leader on November 11, 1975.

Whitlam's removal by the Crown's chief agent in Australia, while legal, outraged the commonwealth, and strained relations with the UK, though in a subsequent election, the public overwhelmingly endorsed Kerr's choice of Fraser as leader, and Labor suffered a landslide defeat.

The documents released Tuesday, which include 211 letters amounting to 1,200 pages of correspondence, show Kerr was in extensive contact with the Palace ahead of and during the move, but ultimately acted on his own.

Kerr appears to have been concerned that a failure to act might have resulted in him losing his position. In one letter, sent to the Palace on October 17, 1975, Kerr warned that "the country is set on a collision course now of historic proportions."

The Queen's personal secretary, Martin Charteris, responded that Kerr was playing his "vice regal" hand with "skill and wisdom." As part of his role, Charteris was the official channel between Kerr and the Queen.

"The fact you have powers is recognized," Charteris added. "Is it also clear you'll only use them as a last resort."

That he did so a month later. In a letter to the Palace notifying them of Whitlam's dismissal, Kerr wrote that "Whitlam came to see me ... (and) I told him that I had decided to terminate his commission."

"He said, 'I shall have to get in touch with the Palace immediately.' To this I replied that this would be useless as he was at that time no longer Prime Minister," Kerr added.

Had Whitlam advised the Queen to sack Kerr as governor-general, she would have had little choice but to do so, or risk an even greater constitutional crisis. While not addressed directly, this does appear to have been a concern of Kerr in not warning Whitlam in advance of his plans, or giving him a chance to demonstrate he could maintain the confidence of Parliament.

In a response to Kerr, Charteris approved of his decision not to tell the Queen in advance, and appeared to support the move to sack Whitlam.

Court battle

The declassification of the papers follows a years-long legal campaign by Australian academic Jenny Hocking, who sued the National Archives for access to them in 2016.

During his time in office, Kerr boasted of his strong links to the Palace, and there had long been speculation that his correspondence with the Queen might have revealed her involvement in the removal of Whitlam, Hocking has said.

She won a landmark court ruling in May this year, with the government given 90 days to examine and, if necessary, redact parts of the papers before publishing them.

Speaking during a press conference Tuesday, National Archives Director-General David Fricke praised Hocking's tenacity, and said that while the two were on opposite sides of a "remarkable" court battle, they ultimately agreed on the importance of the documents concerned.

"We are a pro-disclosure organization but we do things according to law," Fricke said, referring to the Archives Act that governs disclosing classified documents. "We are and we must remain a trusted public institution."

Writing this week, Hocking said that "it was not only the obvious importance of letters between the Queen and the governor-general, her representative in Australia, relating to Kerr's unprecedented dismissal of the elected government that drove this case."

"It was also the importance of asserting the right of public access to, and control over, our most important archival records," she said, adding that, as well as the immediate case, the decision "provides a rare challenge to reflexive claims of 'royal secrecy,' (in Australia) and elsewhere."

"Its implications will be felt broadly in other Commonwealth nations and potentially in the United Kingdom, where the Royal Archives are firmly closed from public access except with the permission of the monarch," she wrote. "Of equal importance is that the High Court's ruling has brought the Palace letters firmly under Australian law, ending the humiliating quasi-imperial imposition of the Queen's embargo over our archival records, and over our knowledge of our own history."

Kerr had requested that the files only be released with the express permission of the Palace, which, according to Hocking, had requested they remain embargoed until 2027 "at her Majesty the Queen's instructions."

Despite the Palace's ongoing objections, however, the High Court ruled that the documents should be made public as official papers relating to the Australian government.

CNN's Hilary Whiteman and Angus Watson contributed reporting.