The Democratic Alliance's (DA's) Western Cape executive wants to get rid of Cape Town Mayor Patricia de Lille, who is in the eye of a political storm involving allegations of cover ups and irregularities.
A source with close knowledge of events said the DA in the province wants her removed.
De Lille on Wednesday said the regional executive had no mandate to make the decisions.
She was preparing a media statement on the matter.
This weekend the DA's federal executive will consider her response as to why she should not resign and then advise her on what it finds.
De Lille's response relates to a report on findings by what has become known as the "Steenhuisen commission".
A subcommittee, headed by parliamentary whip John Steenhuisen, was previously established by the DA's federal executive to look into political management in the City of Cape Town. It is understood several allegations were made against De Lille.
Independent investigators from Bowman Gilfillan Attorneys compiled a report, which also covered allegations faced by De Lille.
It found she may be guilty of gross misconduct for allegedly advising City manager Achmat Ebrahim that he need not report to the City council an allegation of misconduct against Melissa Whitehead, the commissioner of the transport and urban development authority, relating to alleged irregularities involving payments to Volvo for bus chassis.
The Bowman Gilfillan report said a forensic report presented prima facie evidence that "the Commissioner (Whitehead) was involved in irregular expenditure in relation to payments in the aggregate amount of R43 801 807.06 made to Volvo for 29 bus chassis."
It also found that payments totalling R29 584 368 made to Scania for 24 bus chassis during June 2014 were irregular.