They had been left out of an event, promoted as the Powerbrokers and "King and Queen makers" debate, which will be filmed tomorrow in Auckland but air on Newshub Nation on Saturday morning.
It will include Act leader David Seymour, Green Party co-leader Marama Davidson, Māori Party co-leader John Tamihere and NZ First leader Winston Peters.
This afternoon, Justice Tracey Walker heard arguments from Advance NZ's lawyers Honor Lanham and Jordan Grimmer and MediaWorks' counsel Justin Graham.
Both Te Kahika and Ross were at the hearing and watched from the public gallery.
Lanham said the TV network's criteria for which political parties would be included had ignored new parties, those with "gaining support" and the fact Ross is a sitting MP who has been elected three times before.
Advance NZ, she argued, believes it has a "good prospect" of winning the Māori electorate of Te Tai Tokerau, which Te Kahika is standing in.
Support on social media for Advance NZ was also prevalent and higher in some circumstances than the Labour or National parties, Lanham added. While a recent 1 News-Colmar Brunton poll had the party at 1 per cent, the same as the Māori Party and NZ First.
"Social media is a growing means of how parties communicate with the public," Lanham told the court. "But televised debates are [still] of critical importance in an electorate cycle."
"Not all voters will use or have access to social media."
Graham said the debate's selection criteria involved having party leaders who have won seats for their party in either of the last two parliamentary terms.
"Simply put, they don't meet the criteria," he said.
Advance NZ co-leaders Billy Te Kahika, left, and Jami-Lee Ross address the crowd at an anti-lockdown rally in Auckland this month. Photo / Peter Meecham
Graham added Advance NZ has other opportunities to convince people to vote for them, including a TVNZ debate.
Advance NZ will take part in TVNZ's minor party debate because its criteria includes current sitting members of Parliament. Ross is Botany's MP but has dropped out of the race ahead of the October 17 election.
If the debate, which is due to have a live audience of 60 political scientists and commentators, was unable to proceed tomorrow it wouldn't be rescheduled and a significant cost for venue hire would be lost, the court heard.
MediaWorks had also argued there were logistical issues about adding an extra party to its debate because of Covid-19 social distancing requirements.
Justice Walker reserved her decision, which she indicated would be delivered after 11am tomorrow.
Outside court a buoyant Te Kahika told the media that Advance NZ was a "viable new party".
"We should be at all of these televised debates, we believe that our stance is right, we believe our stance has the legal precedent to be supported today, and I'm looking forward to the results."
Thousands of the party's followers have marched and rallied against Covid-19 restrictions and lockdowns this year.
Before the 2017 election, The Opportunities Party (TOP) filed an application for an urgent judicial review after TVNZ excluded its founder and then leader Gareth Morgan from its debates.
However, in 2014 then Conservative Party leader Colin Craig successfully challenged MediaWorks in court after not being invited to the minor parties' debate.
And in 2005, the High Court also ruled in favour of United Future leader Peter Dunne and Progressive Party leader Jim Anderton being added to TV3's leaders' debate.
