The legal challenge will be heard in the court on September 5 and 6, Chief Justice Susan Kiefel told a directions hearing in Sydney this afternoon.
Results would be expected in November and if the majority voted in favour of marriage equality, a free vote would be held in Parliament in early December.
WHATEVER your thoughts are about the postal same-sex marriage plebiscite, I'd urge everyone eligible to cast a vote not boycott it.
It is unclear at this stage if the cases will be joined.
Deputy Senate leader Mathias Cormann said Turnbull's government is "absolutely committed" to "give the Australian people a say on whether or not the definition of marriage should be changed", after their meeting Monday.
Sanchez to miss start of season for Arsenal
There are weaknesses with all of them, whether it's in attack or defence, and quite frankly, a lot of them are much of a muchness. We have been shocked a few times but the target this time is to start in a strong way against a very hard team in Leicester .
"We have serious doubts and grave concerns about the validity of the government's expenditure in this matter and we think these issues need to be determined by the court", she said.
Marriage equality was based on a broad ideal of equality in an Australia that included everyone, but at present gay and lesbian Australians were excluded.
Several Liberal Party lawmakers have expressed exasperation with the handful of colleagues, including former Prime Minister Tony Abbott, who have resisted a simple vote in Parliament.
Pollster Martin O'Shannessy said a market researcher would be able to provide a more accurate picture of Australians' attitudes toward gay marriage through telephone polling for less than AUD1.2 million.
"We're going to see another situation like Ireland where you saw tens of millions in overseas money coming in to influence the debate".
In less than 24 hours their respective crowdfunding campaigns raised more than $100,000 to cover the cost of the High Court challenges.
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The nation's top elections official, Wafula Chebukati, said the vote was carried out in a "free, fair and credible manner". The electoral commission said this was "illegal and premature", and said basic mathematical errors had been made.
Turnbull said Tuesday if Parliament rejected the plebiscite a voluntary national postal vote would be held instead without parliamentary approval.
Former High Court judge Michael Kirby has also spoken of wanting the plan abandoned, saying he is instead happy to wait to Wednesday his partner of 50 years.
'I am planning on doing everything in my power to get my say in this plebiscite, ' Lucinda Bayly told AAP.
He goes on to sing about Australians having an global reputation as being "a little bit racist", as well as homophobic.
"The condescending s**ts think by making it postal, young people won't vote. prove them wrong", the message concluded.
Mauricio Pochettino promises new signings are coming to Tottenham this summer
Tottenham are Sky Bet's 7/10 favourites for Super Sunday's opener with Newcastle 18/5 for the win, while a draw is priced at 14/5. With Betfair having enhanced the price on away win to 25/1, you should probably consider backing Mauricio Pochettino's side.
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