A prominent monarchist is calling for a change of leadership in the movement, amid increasingly bitter divisions among rival organisations.

Key points: Growing disagreements between ACT Council of Australians for a Constitutional Monarch members

Growing disagreements between ACT Council of Australians for a Constitutional Monarch members Calls for leader David Flint to resign due to political bias

Calls for leader David Flint to resign due to political bias Tensions between monarchists come during push for republic

Tensions between monarchists come during push for republic Rival monarchist group says ACM too focused on the "celebrity" of the royal family

Neil James, who sits on the ACT Council of Australians for a Constitutional Monarchy (ACM), told the ABC the group's leader David Flint was undermining the organisation's effectiveness.

"Part of the problem is Professor Flint is closely identified with one side of politics," he said.

"I think it would help if ACM had more of an apolitical front window."

Though he said he was not aware of immediate plans to remove Mr Flint, he urged the group to begin down such a path.

"I think it is something ACM will have to address and address quickly or we will continue to be on the back foot."

Mr Flint said members of the group came from a range of political backgrounds.

"I am more conservative, but we have a very broad-based leadership at the ACM," he said.

"For example, one of the very prominent leaders of ACM is Lord Doug Sutherland — the former Labor Lord Mayor of Sydney.

"We have Labor people on our executive, and when we speak on constitutional monarchism matters, we speak unified, and we have in fact no biases in relation to different parties."

The split emerged just days after republicans launched a new push to ditch the monarch as Australia's head of state, with all state and territory leaders except Western Australia's Colin Barnett signing a declaration saying they want an Australian in the role.

ACM was once the dominant anti-republican voice outside Parliament.

Mr Flint said the monarchist groups were never one organisation.

"ACM got 72 per cent of the vote and therefore provided the leadership, but we were absolutely a united front," Mr Flint said.

"And in fact, on the 11th of November last year, we held a summit, a monarchist summit, which covered the five present constitutional monarchist groups in Australia."

The head of Australians for a Constitutional Monarchy Professor David Flint is accused of bringing political bias to his role. ( Mick Tsikas: AAP Images )

Mr Flint said there had been disagreements between the groups.

"Occasionally we do disagree," he said.

But ACM's influence has waned while a rival organisation, the Australian Monarchist League (AML), has been gaining media traction.

Its 21-year-old spokeswoman Gabrielle Hendry said the AML aimed to encourage young Australians to join the movement.

"We do a lot of media training for our young people so they can go out there, reach out and tell people about the debate," she said.

"We also have different events, toasts, movie nights, really fun things."

Mr James criticised the league as "royalists" who focused on the celebrity surrounding the crown, rather than its place in the constitution.

"It is more than suspicious that the media continue now to go to the Monarchist League rather than reasoned constitutional monarchists who can offer a sound answer to republican proselytising."

Ms Hendry said it would be "great" if the leadership of both groups could "resolve their differences".

"Until then, I'm going to function as best as I can."