The ANC has threatened to lodge a High Court application to have the awarding of the controversial GladAfrica tender set aside, should Tshwane mayor Solly Msimanga fail to have it put under judicial review.
Engineering company GladAfrica and the City have been at the centre of allegations of tender irregularities for the past two months. It was reported that GladAfrica scored a R12bn deal to provide the City with project management support.
In a letter from their attorneys, sent on Wednesday, the ANC said: "We need not remind you that an invalid and improper administrative decision taken remains until set aside by an order of the court."
"The failure to take this administrative decision on review comes at the cost of the people of Tshwane where hundreds of millions of rands would be improperly and unlawfully spent while the people of Tshwane are denied basic services owing to the fact that there are insufficient funds."
The ANC claims that it communicated its concerns about the tender to both Msimanga and the City council.
"You are acutely aware of the provisions of Section 32 of the Municipal Finance Management Act insofar as they relate to political office bearers regarding unauthorised, irregular or fruitless and wasteful expenditure," read the letter.
The party also claims that GladAfrica's appointment contravened the act and did not comply with a transparent procurement process.
On Tuesday, Tshwane City manager Moeketsi Mosola headed to court in a bid to halt a preliminary report into the GladAfrica scandal from being handed out in the council.
The urgent application is expected to be heard on Thursday - the same day the report is expected to be handed out to the council.
Mosola is seeking to have the decision for an investigation into the matter deemed unlawful and wants to stop the investigation.
The court application is perceived to be a delaying tactic by Mosola who hopes to avoid the possible damning finding against him contained in the preliminary report.
In his founding affidavit, Mosola writes that he has no quarrel with the council's decision to investigate the allegations of misconduct in the GladAfrica transaction. He adds, however, that he disputes the legality and the lawfulness of the process that council has chosen to follow.
In August, Tshwane mayor Solly Msimanga attempted to suspend Mosola on the back of the allegations, but he was unsuccessful.