The hearing is set to conclude a long-running battle over governance which has involved players, administrators and the Tongan government.
TNRL Secretary William Edwards will be participating in the hearing via video conference from Auckland, where he's been situated since New Zealand's first lockdown in March, when he was forced to miss the Special General Meeting where full members voted on the expulsion.
Three arbitrators are expected to hear the arguments, with Covid-19 forcing the officials to beam in from far-flung locations.
"We nominated one from Australia, they (IRL) nominated one from England and then the Court of Arbitration selected one independent from America, so that creates a logistic nightmare in itself because there's three arbitrators in three different jurisdictions," Edwards said.
"...so here in New Zealand it will be 9 in the morning on the 23rd of September, which is the 22nd Swiss time, and it will be (7) in the morning Australia time, so they've given us a timetable for around the world and what time people will be logging on to participate in the hearing."
Alongside Edwards, TNRL's witnesses appearing before the hearing include a government minister, three club representatives and a tournament committee manager, who will dispute what they believe were "false statements" made by the IRL, leading to their suspension and eventual expulsion from the international governing body.
"[TNRL's] evidence and the board minutes goes to the facts that they relied on to suspend us, that we didn't have the support of the clubs, which is a lie, so they never should have suspended us and basically that was the evidence they used they didn't give to us," he said.
"It's in their IRL minutes, but he didn't mention it to us and if [that was the case], we would have called the clubs. But he didn't say anything to us, so it's a submission he makes to the board and they say 'okay, sack them'."
The Asia-Pacific Rugby League Confederation has already recommended a new governing body to represent Tonga, with Tonga Ma'a Tonga Rugby League's (TMTRL) bid for full membership of the IRL also having the support of the current Tongan players and coach.
TMTRL Chairman Semisi Sika was President of the Tonga National Rugby League when the board was dissolved by a court order in 2016 for "financial mismanagement".
William Edwards is disappointed that the current TNRL administration has not been given a real opportunity to prove themselves.
"If they give us the chance to put forward the documents...because [APRL Head of Operations] Gareth Holmes wrote in his report that there has been significant improvement and so forth, he's admitted that we've gone and improved, and yet they're saying there's mismanagement," he said.
"Everyone got caught up on the fact that they thought that you know, we'll get behind the players because the players were right...but they don't understand that the players were used.
"These are all internal matters and they should have just left us alone to do it ourselves, and the supreme court in Tonga is available to them."
The International Rugby League did not want to comment publicly on the upcoming hearing when contacted by RNZ Pacific.
However, Global Operations Manager Danny Kazandjian said both legal teams were working together on some preliminary issues and IRL "would like to see the outcome of those efforts before committing to anything."