The court ruled new electoral rules approved by parliament are valid.
Under the new process, electors who wish to vote above the line are required to number at least six squares on the ballot paper.
Below-the-line voting requires them to number at least 12 candidates in order of preference.
The court ruled voters were not disenfranchised by the new process, and there was no infringement of the implied freedom of political communication or the system of representative government.
Prime Minister Malcolm Turnbull, campaigning in Adelaide, was not surprised by the decision.
“The High Court’s decision is entirely as expected,” he told reporters.
Family First senator Bob Day, who was party to the challenge, said the decision meant the bar had been set high for any minor party or independent to win a Senate seat.
“What the parliament, the major parties, the Greens, Nick Xenophon did was take away voters’ rights and punish those voters who vote for minor parties by threatening to kill off their votes,” he told reporters outside the court in Canberra on Friday.
Liberal Democrat senator David Leyonhjelm said any candidate who didn’t have incumbency or $20 million to spend as Clive Palmer did at the 2013 election would never succeed.
Opposition Leader Bill Shorten, campaigning in Sydney, was unimpressed by the decision.
“I think the outcome there is about as surprising as real estate agents losing their negative gearing taxpayer-funded subsidies,” he told reporters.
Labor voted against the changes in parliament but didn’t have the numbers in the Senate.
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