The Western Australian Premier Colin Barnett says it is not entirely clear how the State will move towards a Senate re-election.

The High Court ruled today that WA will go back to the polls for a new Senate election, after September's result was declared void.

The Australian Electoral Commission (AEC) had petitioned the court asking for the Senate results to be discounted after 1,370 votes could not be found for a recount.

Mr Barnett has told State Parliament the steps towards a re-election are "new territory" in terms of legislation and the Constitution.

The only precedent was in 1907 in South Australia when there was a re-vote for a single Senate position.

Mr Barnett says he will be seeking advice but believes it will be up to him to go to the WA Governor Malcolm McCusker asking for a writ to be issued to elect six senators.

The writ will outline all the key timings for the election, including the dates for the close of the electoral roll, candidate nominations and the day of the election.

Mr Barnett says the Commonwealth Electoral Act of 1918 regulates the election of Members of the House of Representatives.

"What is less known is that the Election of Senators Act 1903 is West Australian legislation, that regulates the election of senators from Western Australia," he said.

"Each state has equivalent legislation obviously in the early years of Federation."

Special Minister of State and Liberal senator Michael Ronaldson, the federal minister responsible for the AEC, says it would be inappropriate for him to comment on the court's findings.

"However, the people of Western Australia, having cast their vote at the last federal election, will rightly be aggrieved that the actions of the Australian Electoral Commission will force them to vote again in a fresh election," he said in a statement.

"It is incumbent upon the Australian Electoral Commission to ensure that never again will such a failure of process occur, as it did with the 1,370 lost votes."

Earlier this week, Justice Kenneth Hayne found "the only relief appropriate is for the election to be declared void" because the loss of the ballot papers had prevented electors from voting.

He also ruled that Greens senator Scott Ludlam and the Australian Sports Party's Wayne Dropulich were not duly elected.

Submissions from the Labor Party and the Palmer United Party (PUP) that the first result be upheld were dismissed.

That original count resulted in success for three Liberal candidates, two from Labor and one from the PUP.

However, the closeness of the count in the final two seats won narrowly by Labor's Louise Pratt and the PUP's Zhenya "Dio" Wang, resulted in a challenge by Senator Ludlam and Mr Dropulich, and a recount was ordered.

On the recount, which excluded the missing ballot papers, Senator Ludlam and Mr Dropulich won the spots.

Labor looking to do better

Federal Opposition Leader Bill Shorten says it would be good if the ALP could pick up two seats in the re-run poll.

"Labor's been electorally challenged in Western Australia in the last couple of elections - let me put that another way - we haven't done very well," he said.

"Our challenge is to connect with West Australians. The State Opposition led by Mark McGowan is doing a reasonable job. Colin Barnett is perhaps not travelling as well as he would like in the polls over there."

Labor senator Louise Pratt, who won in the first count but lost in the recount, says she believes voters will see that Labor can provide stability.

"We have a Senate before us which has a range of minor parties within it. There is every chance of a lot of confusion and problems for our nation unless we've got a Senate that can actually hold the Government to account," she said.

"The election of Labor senators in this state will really help deliver that."

Until today, Mr Dropulich was a senator-elect. He says he is ready for a fresh election.

"(The) justice has handed down his decision. Obviously we're going back to the polls now. It's obviously not [just] disappointing for us, but I feel it's disappointing for all West Australians," he said.

"Obviously taxpayers now have to foot the bill for this new election and also having to go back to the polls. It's an unfortunate situation but that's the way it's turned out."

WA Liberal Senator Mathias Cormann has pitched his party's message for the campaign.

"The Liberal party has a strong and experienced team which will deliver for Western Australia," he said.

"Only the Liberal party is committed to scrap the anti-WA carbon tax, the anti-WA mining tax.

"People across Western Australia face a clear choice, between the Liberal Senate team who will scrap these anti-WA taxes or vote for Labor and the minor parties who want to keep it."



Decision opens seats to challenge

ABC election analyst Antony Green says in his blog the ruling will be a blow to the Abbott Government.

"Of the six seats up for election last September, four seats were unaffected by the closeness of the count," he said.

"Those senators whose election was not in doubt included all three elected Liberal candidates.

"While two Senate seats were left in doubt by the count, the only option open to the court was to void the election of all six senators and re-run the election."

Mr Green says a re-election could put one of the Liberals' seats in doubt.

"Alternatively the Liberal Party could maintain its support from last September, and possibly turn the election into a referendum on the repeal of the carbon and mining taxes."