Australia's six state premiers have stated they will not be attending King Charles reception in the capital, Canberra, when he arrives next week.
The move has been labelled an "insult" and disrespectful by pro-monarchy group, Australian Monarchists League, as the debate around the country becoming a republic is reignited.
When the 75-year-old ascended the throne after his mother's death in 2022, republic supporters in Commonwealth countries began to question their future under the monarchy.
Last week, Buckingham Palace responded to the Australian Republic Movement on behalf of the King, confirming it is a "matter for the Australian public to decide".
The group is describing the royal's Australian visit - his first to a Commonwealth country as monarch - as his "farewell tour", even selling merchandise to campaign for the move.
Now the premiers of New South Wales, Victoria, Queensland, Western Australia, South Australia and Tasmania have said they are too busy to attend King Charles and Queen Camilla's reception, where he will be formally welcomed by Prime Minister Anthony Albanese on Monday.
Victoria premier Jacinta Allen, who supports Australia becoming a republic, told reporters she was pleased the royal was visiting but she couldn't attend because had a number of "long standing engagements, internal and external".
"The government and the community will be very well represented by the governor and the parliamentary secretary."
Australian Monarchists League spokesperson Beverly McArthur, who is also a Liberal MP for Western Victoria, told ABC News radio it was disrespectful.
"She [Allen] should represent Victorians because we pledge allegiance to the monarchy when we sign up to be a politician."
She said the "excuses" made were extraordinary and not attending was an "insult".
"I find it insulting, I think they should just taking off their republican hats, make the short trip to Canberra, say 'hi and thank for coming to Australia' and return.
"I think it's appalling that Jacinta Allen is not going to Canberra."
Sky News reported NSW Premier Chris Minns could not attend due to a cabinet meeting, but will meet the royals at other events during their visit. Queensland Premier Steven Miles cannot attend because he is busy with his re-election campaign. And Tasmanian Premier Jeremy Rockliff and South Australian Premier Peter Malinauskas were also preoccupied.
A spokesperson for Western Australia's Premier Roger Cook reportedly said he had "other commitments".
Earlier this year, the Australian government postponed plans to hold a referendum on removing the King as head of state.
King Charles is expected to be pausing his cancer treatment while on the tour, which will also include travelling to Samoa for the Commonwealth heads of government meeting.