John Howard, the Prime Minister, and an ardent monarchist, wants the Queen left out of the question. Republican leaders accuse him of trying to rig the result by subterfuge. "The question is this: do Australians want King Charles III as our next head of state?" asked Malcolm Turnbull, chairman of the Australian Republican Movement.
Kim Beazley, leader of the Labor Party opposition, said: "Make no mistake about this. If we vote for somebody else's head of state to continue as our own we'll be something of an international laughing stock."
The issue will come to a head on Monday when a parliamentary committee in Canberra is due to deliver its report on the wording of the ballot question. After an inquiry lasting several months, the crossbench committee has concluded that the Queen should be mentioned.
It proposes a vote for or against "a Bill for an Act to alter the Constitution to establish the Commonwealth of Australia as a republic with the Queen and the Governor-General to be replaced by an Australian president". Mr Howard wants a vote on "a Bill... to establish the Commonwealth of Australia as a republic with a President chosen by a two-thirds majority of the members of the Commonwealth Parliament".
The difference in wording is crucial. Republicans argue that Australians should be confronted with the central issue, which is to cut the final constitutional link with Britain. The Howard version, they say, is weighted against a yes vote, because it focuses on the way a new Australian head of state would be appointed, through parliamentary consensus. Opinion polls suggest most Australians are unhappy with this republican model, and would prefer to elect their head of state directly, bypassing parliament.
The question has to be settled with enabling legislation by Friday for the referendum to be on schedule. Republicans have been given the jitters by recent polls that show support for their cause falling below 50 per cent for the first time. This could reflect public confusion as the campaign grows - and ministers in Mr Howard's conservative coalition government are feeding the confusion.
One of Mr Howard's senior ministers, Peter Reith, declared himself a republican last Monday but called for a "no" vote in the referendum - he wants the president elected directly. And on Wednesday, Peter Costello, the Treasurer (or Chancellor), called for a "yes" vote, and for the Queen versus Australian version of the question. The ministers' interventions could be rival posturings to succeed Mr Howard as leader of the Liberal Party. If so, such cynical manipulation of the referendum campaign does not bode well for its success.