National Assembly Speaker Baleka Mbete is a "player" for President Jacob Zuma's ANC, the DA said on Tuesday.

Calling on MPs from all parties to support a motion of no confidence in the Speaker, Democratic Alliance parliamentary leader Mmusi Maimane said Mbete had a conflict of interest.

"Let me be clear, this motion is not personal. This is not about Baleka Mbete. Honourable Mbete is a competent member of this House. She's a former deputy president. She has her flaws, but we respect her as an experienced politician.

"What this motion is about is about the office she holds in the ANC, and what it means to holding the office of Speaker."

Mbete could not serve as a leader of the ANC and a neutral Speaker.

"The conflict of interest is untenable."

Mbete had been deployed as Speaker to ensure Zuma did not have to face any tough questions.

"She came here not as an honest referee, but as a player for President Zuma's ANC. She sold out this Parliament to her masters at Luthuli House," Maimane said.