High Court Justice Kenneth Hayne stopped short of formally ordering a new election but his judgment yesterday pointed to it being the only option to resolve the WA Senate debacle.
Justice Hayne, sitting as the Court of Disputed Returns, found the Australian Sports Party's Wayne Dropulich and Greens Senator Scott Ludlam were "not duly elected" to the fifth and sixth Senate seats at the September 7 poll.
He rejected the idea the court was empowered to decide who should get the final two seats.
Justice Hayne reserved his final decision until tomorrow but ruled on three questions of law before the court.
He agreed with the Australian Electoral Commission that the 1370 voters whose ballot papers were lost because of an official error were effectively "prevented from voting".
This was because their vote was not counted in the crucial re-count and given the closeness of the race, it was inevitable to conclude this probably affected the result.
"It is not possible to determine who was duly elected because ballot papers have been lost," Justice Hayne said.
"All parties rightly accepted that, if the court declares that Mr Dropulich and Senator Ludlam were not duly elected, and cannot declare who was duly elected, the only relief appropriate is for the election to be declared void."
On the second legal question, Justice Hayne said it was inadmissible to include records of the original count of the missing papers in the re-count.
"No provision of the (Electoral) Act expressly provides for making such a patchwork of results," he said.
For the third legal issue, Justice Hayne dismissed Labor and the Palmer United Party's plea for the court to re-examine 949 challenged votes.
The parties argued officials wrongly counted these votes and a review would turn the election in their favour.
Constitutional law expert George Williams said the judge effectively ruled the court could not reconstruct the result and it was almost certain WA would have a new Senate ballot.