Buckingham Palace and Australia's governor-general engaged in inappropriate and alarming political discussions before the 1975 dismissal, the academic behind the palace letters' release says.
Professor Jenny Hocking said it was totally improper for the governor-general and the Queen's private secretary to discuss the use of Sir John Kerr's "arcane" reserve powers to sack prime minister Gough Whitlam.
Prof Hocking said two letters from the Queen's secretary Sir Martin Charteris in the week before the dismissal were scandalous, as he gave advice on the highly-contested use of his reserve powers.
"For the Queen's private secretary to be commenting to the governor-general, who is about to exercise those powers, on the existence and possible use of those very powers, I think is alarming," she told reporters in Melbourne on Tuesday.
Prof Hocking said Sir John had refused to discuss his options with Mr Whitlam and refused to accept the solicitor-general and attorney-general's advice about the possible use of the reserve powers.
"He is instead taking advice from the Queen's private secretary on that question," she said.
She described it as a troubling discussion.
"There is no doubt that they had conversations that clearly affected the decisions that Kerr made and the way in which he made those decisions."
She said it was also inappropriate for Sir John to talk to Prince Charles about his concerns that he may be sacked as governor-general, a discussion the Prince of Wales then shared with the Queen.
"These are not appropriate conversations to be had between a governor-general and a member of the royal family,.
"It's very concerning that those conversations were had and that the Queen then engaged in them further."
The palace was aware of the possibility of the dismissal, but not when that would happen, Prof Hocking said.
Prof Hocking said the head of a constitutional monarchy must at all times remain politically neutral and remain above the politics of the day.
But she said the letters showed Sir John communicated with the Queen about political matters, and the monarch in response engaged with that conversation at a very political level.
"You could not get more political than the crisis in the Senate that the government faced, and the eventual dismissal without warning of the elected government."
Australian Associated Press