Mining magnate Gina Rinehart's youngest daughter has launched a last bid effort to keep her family's trust fund battle from being played out in open court.
Lawyers for Ginia Rinehart - who has sided with her mother in the family dispute - sought leave to appeal a Supreme Court decision on Wednesday in a push to get the proceedings referred to arbitration.
The move comes just days before the civil trial is set to begin and in the wake of her mother's declaration on Tuesday that she wishes to relinquish control of the multi-billion dollar family trust and bring an end to the proceedings.
John Hancock and Bianca Rinehart allege their mother acted "deceitfully" and with "gross dishonesty" in her dealings with the trust, set up in 1988 by her father, Lang Hancock, with her children as the beneficiaries.
The court has previously heard that days before the trust was due to vest, Ms Rinehart contacted the children warning that if it did, they would be liable for substantial capital gains tax.
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The two children claim this was an attempt to mislead them.
They also allege that Ms Rinehart changed the constitution of the family company, Hancock Prospecting Pty Limited in 2006, in such a way as to prevent her being removed as trustee.
Last month lawyers for Ms Rinehart - who has consistently denied the claims - sought to get the proceedings heard behind closed doors, saying the fresh allegations about the company's constitution fell under the terms of the family trust fund deed and therefore should be referred to arbitration.
But this application was dismissed.
On Wednesday Richard McHugh SC on behalf of her daughter Ginia Rinehart made an application for leave to appeal this decision.
Mr McHugh said the claims about changes to the company's constitution were only made in August and that as of 2006 Bianca Rinehart was the director of the family company and therefore had full knowledge of any such changes.
But Christopher Withers, who represents Mr Hancock and Bianca Rinehart, described the appeal as "futile" and said much of the details surrounding the claim had already been made public.
He also said that regardless of Bianca Rinehart's knowledge, Mr Hancock's claims against his mother still stood and would proceed to trial next week.
"We only need one plaintiff in order for the dispute to go ahead," he said.
Mr Hancock and Bianca Rinehart were previously supported by their sister Hope Welker, but she withdrew from the case earlier this year.
Justices Robert Macfarlan and Anthony Meagher have reserved their decision until Thursday.
