Des van Rooyen, who was appointed finance minister by former president Jacob Zuma for a calamitous weekend in December 2015, wants to apply for leave to cross-examine former Treasury director general Lungisa Fuzile at the state capture commission of inquiry.
Van Rooyen has also indicated his interest in testifying before the commission.
But inquiry chairperson, Deputy Chief Justice Raymond Zondo, postponed the application, saying that a fresh date would have to be arranged.
"It is important that this commission be fair to all parties," he said.
Van Rooyen's lawyer Kgomosoane Mathipa told Zondo the commission's legal team indicated that it did not oppose the application.
Mathipa said they were in the process of completing supplementary statements for their client.
However, evidence leader, advocate Vincent Maleka, SC, raised some concerns with Van Rooyen's application.
"We are in this difficulty because of the lateness of the application," he said.
Maleka told Zondo: "We will ask you to consider what is in the best interest in the work of the commission. We understand that there is a need to be fair to Mr Van Rooyen but we will ask you, as you consider the question of fairness to Mr van Rooyen, that we are in this difficult position because of the attitude he has taken, an attitude which arises from his papers before you."
Maleka said there was an application for condonation before Zondo because Van Rooyen's applications came a month later than the time period it was required for him to submit.
"Fairness requires that as you consider the conflicting ... take into account that we are in this difficult position because of the late choice he made," he said.
During his testimony last year, Fuzile testified that Van Rooyen allegedly arrived at the National Treasury with a pre-appointed adviser.
Fuzile also testified about the impact Van Rooyen's appointment had on the Treasury - one of the country's most respected institutions.
Fuzile said he was "taken aback" the moment Mohamed Bobat introduced himself as Van Rooyen's adviser ahead of the ill-fated swearing in of South Africa's shortest-serving finance minister.
He added that he was further shocked when Bobat allegedly gave him instructions.
Fuzile also revealed that on the evening Nhlanhla Nene was axed as minister (December 9, 2015) he received a call from the head of the ANC's economic transformation committee, Enoch Godongwana, who told him: "You are now going to get a Gupta minister who will arrive with (Indian) advisers."
While Fuzile said he tried to give Van Rooyen's appointment the benefit of the doubt, when he met Bobat, he realised that Godongwana's warning was, in fact, true, News24 previously reported.
The commission continues with Fuzile's testimony.