One of Australia's favourite election traditions, the moment when ABC chief elections analyst Antony Green declares a result, could be significantly delayed if a challenge launched by United Australia Party leader Clive Palmer is agreed to by the High Court.

Key points: Mr Palmer says publication of preferences before western polls close could bias result

Mr Palmer says publication of preferences before western polls close could bias result Antony Green says a Palmer win could take election coverage back to 1990

Antony Green says a Palmer win could take election coverage back to 1990 High Court will consider whether AEC's current practice is unconstitutional

Lawyers for Mr Palmer will today call on the court to ban the Australian Electoral Commission (AEC) from revealing preference results before all polls have closed.

That would mean only basic first preference votes could be publicised before 9:30pm AEST — when the last polling booths closed in the Cocos Islands.

But Green said some figures would still be up for discussion once polls closed in the eastern states.

"It won't be the end of election night but it'll wind back the clock to 1990 before the electoral commission started to do preference counts," he said.

"We'll still have the first preferences, we'll still be able to report those numbers to the people in Western Australia, we'll still have scrutineers figures, we'll still be able to estimate two candidate preferred preferences, but what we'll lack is an official and accurate count."

Mr Palmer's case takes aim at the AEC's Two Candidate Preferred (TCP) counting practice.

If Mr Palmer wins his case, Antony Green may have to wait a lot longer to name a winner on election night.

In the lead up to each poll the AEC identifies the two most likely candidates for each electorate.

It then names them on election night as preferences are distributed ahead of the formal distribution of preferences well after the poll.

This is done to give an accurate early indication of the result.

Mr Palmer's lawyers will argue that publishing those preference results from polling stations on Australia's east coast on election night risked influencing voters in Western Australia and beyond who might not have voted yet.

"Our challenge is to say that that's wrong. That if there is going to be an announcement of what the results are they should be the actual results, not the results that some bureaucrat thought up two weeks before the election," he said during a weekend press conference.

Mr Palmer said the practice risked delivering a contrived result rather than an actual one.

"It impinges upon the integrity of the Electoral Commission and fairness in Australia," he said.

Current system speeds up results

Mr Palmer's lawyers will tell the High Court the practice is at odds with the Constitution.

"Publishing or making publicly available the identity of the TCP candidates or the results of the indicative TCP count while the polls remain open in any part of the nation is not a constitutionally valid exercise of power," their submission to the High Court said.

"Any such publication or public release would impermissibly distort the voting system in a manner that would compromise the representative nature of a future parliament."

Map Cocos (Keeling) Islands

Mr Palmer also argued the system disadvantaged smaller parties like his, but Green questioned whether that was true.

"I'm not really sure what he gains out of this case," he said.

"His argument is the choice of the officials in determining the final two candidates in the eastern states might somehow influence voters in Western Australia about not voting for a minor party."

Green said how minor parties were polling would be revealed by first preference votes anyway.

He also queried whether there was any foundation in the claim voters might be influenced by knowing the earlier results.

"People do not sit around waiting to know what the result is in the eastern states," he said.

"Most people tend to vote earlier in the morning, the voting slows down in the afternoon so the idea of people hanging around in Western Australia to know what the result is just doesn't make sense."

Green said the system of choosing two candidates ahead of election night had served Australia well.

"In 95 per cent of the cases it's obvious who the two final candidates will be," he said.

"There's sometimes dispute over those final two.

"But the only reason it's done is to just try and speed up knowledge of the results.

"The indicative count done on the night and the days afterwards does not determine the winner, the winner is determined at the end of the count with the formal distribution of preferences."

Submissions from the Commonwealth rejected claims the system was not constitutional but said, even if there was a clash, it was justified by the need to deliver a prompt and certain result on election night.

Green said the case had already caused some disruption, as the AEC has yet to release some of the material it would normally have delivered at this stage of the electoral cycle.

Mr Palmer's hearing has been set down for a day.