The Economic Freedom Fighters (EFF) in Tshwane has opened a case of electoral fraud against Democratic Alliance (DA) Tshwane leaders Cilliers Brink and Jacqui Uys for allegedly instructing DA councillors to use identifying numbers in the vote for the Tshwane speaker.

The EFF opened the case at Pretoria Central police station on Thursday. The party said it believed DA members Brink, Uys and Katlego Makgaleng contravened the Municipal Structures Act and the Electoral Act when "they instructed all 69 DA councillors to vote using numbers assigned to individual councillors".

"This was intended to identify the candidate the councillors voted for in the secret ballot. This constitutes fraud [in] a secret ballot process. As such, the law must take its course," EFF Tshwane leader Obakeng Ramabodu said.

The DA and its coalition partners lost the election for speaker by a massive margin, and their candidate, ActionSA councillor Kholofelo Morodi, received only 37 votes.

The DA rubbished the EFF's electoral fraud claims, saying they were designed to draw attention away from the criminal behaviour of the African National Congress (ANC) and the EFF.

Brink alleged that ANC and EFF members attacked a DA councillor on Monday during the council sitting held to elect a speaker.

"This is consistent with the violent behaviour of especially the EFF, who last month also broke into the offices of political staffers and assaulted several officials. In this regard, Obakeng Ramabodu can give his account of his conduct at the police station," Brink said.

The tensions between political parties in the Tshwane council are increasing ahead of a special sitting planned for Friday to elect a mayor. Newly elected speaker Mncedi Ndzwanana scheduled the sitting.

But the DA has written to his office, requesting that he postpone the meeting due to an unrelated march by the ANC in Pretoria.

Brink wrote to Ndzwanana, saying there were "concerns and the risk of violence and intimidation".

"You are already aware that on the same day, the ANC has organised a protest march that will start in Marabastad and end at Tshwane House. The march is directed explicitly against the DA-led administration," Brink wrote in his email to the speaker's office.

He said the Tshwane Metro Police Department did an assessment and recommended that a meeting of the Section 79 standing committee on rules and ethics, planned for Friday, be cancelled due to the ANC march and possible staff constraints at both the council and the ANC gathering.

The speaker's office has not indicated whether it will reschedule the mayoral election. Instead, a media advisory stated that a mayor had to be elected on Friday.