The embattled Tshwane MMC for Roads and Transport Sheila Senkubuge has resigned from her position.
Senkubuge said that despite her work successes, there were efforts to personally drag her name.
"In light of recent events, and despite the many successes, it has become clear that attempts to vilify me are taking focus away from the purpose of my role in office. This will in turn inevitably affect service delivery to our residents."
Senkubuge added that all she had done was "at the behest of the people".
"Therefore, as much as it is with regret that I tender my resignation with immediate effect, I do so in order to not betray the spirit, the struggle and the sacrifice that our forebears made and the charge they gave us, which is to always put our people first, as articulated in the Batho Pele principles."
She said residents had to continue getting "the best level of commitment and services from us, as their leaders".
"I believe focus should always be on one thing and that is improving the quality of life of our people of Tshwane. I remain forever humbled and honoured to have been given the opportunity to serve."
This comes after an audio recording purportedly of Tshwane mayor Stevens Mokgalapa and Senkubuge surfaced last weekend.
In the clip, which has been widely shared on social media, a man and woman can be heard plotting the removal of some of their colleagues. A few moments later, the pair are heard engaging in sexual intercourse.
Mokgalapa took special leave after audio was circulated of him allegedly having sex with Senkubuge while also making several damning comments about his colleagues and political opponents.
They both later denied that they were in a relationship with each other.
Read the letter below: