More than 12.3 million people are registered to vote in the compulsory ballot that will decide if the country should sever constitutional ties to Britain by replacing the Queen Elizabeth II with an Australian citizen as head of state.

The poll, taken this week for the Sydney Morning Herald and The Age of Melbourne, showed support for the ``Yes'' campaign trailing the ``No'' campaign by 41 to 47 percent with undecided voters down to 12 percent from 26 percent a week before.

It also showed republican supporters of direct presidential election voting with the monarchists against the proposed ``minimalist'' republic in which a President would be endorsed by a two-thirds majority of parliament still hold the key.

If the alienated republicans, who make up a third of the ``no'' vote, were toswitch sides, it would boost support for the republic by 15 percent, assuring its easy success, the Herald said.

The poll is the third this week to show fewer than 10 percent oppose the republic because they actually prefer having the Queen as Australia's head of state. The monarchists have kept the Queen well hidden, barely mentioning her at all and instead targeting alleged flaws in the minimalist republic in what has been seen as a highly effective scare campaign. In a late advertising blitz, the republicans are reminding voters she is still the Queen of Australia by lampooning a toast to her majesty by US President Bill Clinton during a visit to Australia a few years ago.

The commercial, seen as a national embarrassment, was held back until the last few days to form part of multi-pronged assault focusing on republican claims that Australia faces international humiliation if it votes for the queen rather than a ``resident for president''.

Polls show support for the republic is highest amongwell-educated high income earners and lowest among the poorly-educated, leading to complaints by the republicans that they are fighting an uphill battle against the ignorance of the Australian electorate.

High-profile monarchist, Professor Leonie Kramer, also told ABC television this week that Australians were not well-versed in constitutional matters and many had decided they were not going to vote for what they did not understand. Leaders of the republican campaign bombarded the airwaves on Friday to issue last-minute warnings to those intending to vote ``no'' in the hope they will be able to vote for a direct-election presidency in another referendum soon.

``They have either been led up the garden path by monarchists or they are naive,'' the Australian Republican Movement (ARM) said. ``Australians should not be fooled into thinking there will be another chance.''

Federal Treasurer Peter Costello, the government's leading republican, said he feared a country which is predominantly republican willstill be monarchist on Sunday morning.

But monarchist Prime Minister John Howard said the great failure of the campaign was that the republicans ``haven't persuaded us that this country will be better'' if it became a republic.

``I don't believe in change for its sake,'' Howard said, adding that the fact that Queen Elizabeth was also queen of other countries was no reason for Australia to sweep away a system which had served it so well.``I say on balance, it is not.''

Frontrunners for `Presidency'