Cape Town Mayor Patricia de Lille and council speaker Dirk Smit are expected to face separate motions of no confidence in the City of Cape Town council on Thursday.
The council returns from recess at 10:00 to debate, among other council business, the future of its mayor and speaker.
The motion against De Lille is the second brought by her own party that she will face in council this year, while the motion against Smit was tabled by the opposition ANC.
De Lille survived a similar motion of no confidence against her in February by one vote.
The mayor on Thursday tweeted she was feeling "positive" ahead of the motion, saying "what must be, will be".
"The motions of no confidence in the past and this one have been on the basis of untested allegations without evidence," she tweeted.
"I remain positive and continue to put the people of Cape Town first."
ANC's motion 'contrived'
DA Cape Town deputy caucus leader JP Smith, who has been critical of De Lille's leadership over the past 12 months, said it would be very difficult to predict the outcome of the new motion against the mayor.
The party and the caucus, however, still believed it was the right thing to do given the raft of allegations levelled against De Lille and the fact that she had lost the confidence of 70% of her caucus.
"The same conditions still apply, and the same reasons for our [loss] in confidence still stand."
He was more confident the motion against Smit would be defeated, saying the ANC's reasoning was "contrived" and none of the DA's councillors had bought the opposition party's argument.
The ANC in Cape Town meanwhile is due to address the media on Thursday morning before the sitting.
Cape Town ANC caucus leader Xolani Sotashe told News24 last week that they had lost confidence in Smit, claiming he had lost control of the council over the last few months.
He also said they would not be supporting the DA's motion against De Lille.
If the motion against De Lille is successful, she will have to resign and the mayoral committee she appointed will be dissolved.
Deputy Mayor Ian Neilson will step in as acting mayor, and the council will have 14 days in which to appoint a new mayor.
The motions against De Lille and Smit will likely take place after lunch on Thursday.