The defence lawyer, who has 46 years' experience, has employed a lawyer to ask to be allowed to practise as a lawyer between now and when his appeal is heard in two months time.
The former high-flying lawyer was found guilty of three charges of professional misconduct by the Lawyers and Conveyancers Disciplinary Tribunal in July. He has since been struck off as a lawyer.
The Tribunal - chaired by Judge Dale Clarkson - said striking off was a "last resort" for the senior lawyer who has represented clients at the Privy Council.
Mr Hart's lawyer Jeremy Bioletti told the High Court at Auckland today that the court had the powers to allow Mr Hart to act as a lawyer before his appeal is heard in December.
"He is seeking a dispensation to allow him to, between now and December 10, be able to move those cases forward, complete them, or whatever is needed or required to complete them," Mr Bioletti said.
He said the Tribunal was acting in the public's interest but Mr Hart's clients would be adversely effected.
Mr Bioletti said if Mr Hart could not represent his clients, his career as a lawyer would be over.
Justice Graham Lang told Mr Bioletti that the rules stated a lawyer was not allowed to practice until their appeal was heard.
He said there was no evidence that Mr Hart would be bankrupted if he was unable to appear.
The hearing is yet to hear from lawyers for the Law Society.
Hart is also appealing the Tribunal's decision which saw his lengthy career brought to an end. A hearing date has been set down for December 10.
The Tribunal's decision found Mr Hart's case was aggravated by his "poor disciplinary history", which included seven previous findings against him.
One for "gross overcharging" was 30 years old, but identical in nature to the latest case.
Mr Hart was found guilty of unsatisfactory conduct for overcharging on two occasions in 2010 and again a year later.
Two other findings of unsatisfactory conduct for failing to pay expert witnesses, again described as identical behaviour to one of the charges in the current case, were made just last month.
The pattern of behaviour meant the tribunal had "no confidence in either his rehabilitation or protection of the public by ensuring there is no risk of reoffending.
"We accept that striking off, particularly in a practitioner of such seniority, is a last resort response," said Judge Clarkson.
"Having weighed all the evidence and submissions it is the tribunal's unanimous view that the practitioner is no longer a fit and proper person to practise as a barrister or solicitor."
The 71-year-old lawyer has also lost his multimillion-dollar properties north-west of Auckland after owing $30 million to the ANZ National Bank. It has also been revealed that his fleet of luxury cars - including an Aston Martin - have been seized by debt collectors.
Mr Hart was ordered to pay 85 per cent of the Law Society's $116,000 costs - a total of $98,000.
