Nompondo said in the letter Mashinini was not authorised or mandated to file an affidavit on behalf of the PEC.
“You are therefore instructed to immediately file with the Constitutional Court a notice of withdrawal of the appeal pending finalisation of unity talks,” the letter said.
“In addition to filing the aforementioned notice of withdrawal, you are instructed to notify the attorneys acting on behalf of the respondents in this matter through a letter informing them of the PEC’s resolve stemming from the guidance of the national leadership not to proceed with the appeal.”
Nompondo also told Moroka Attorneys to take instructions only from his office.
The appeal by the Free State PEC was backed by party secretary-general Ace Magashule, who filed an affidavit in support of the court action.
The SCA ruling spelt bad news for Magashule, as the disbandment of Mashinini's PEC would mean the end of his tight grip on the control of party structures in his home province.
Magashule's affidavit in support of the appeal was another show of defiance after he told provincial secretaries this month to include names of those facing allegations of corruption when sending their lists of those who will be affected by the ANC step-aside rule.
The national executive committee had limited the step-aside rule to those who have been charged in court.