The Democratic Alliance (DA) is to approach the Western Cape High Court to compel President Jacob Zuma to answer a question on the "spy tapes" case.

The DA said on Monday that Zuma avoided accountability in Parliament last week when he refused to answer a question about the legal costs of the infamous "spy tapes" saga.

Rather than giving an answer in rands, Zuma said that the president, like any other employee of the state, was entitled to defend at taxpayers' expense through the State Attorney Act.

But the DA says that the president's refusal to answer amounted to an insult.

"Parliament has a job. Jacob Zuma has a job. You can't pick and choose which questions you want to answer," DA leader Mmusi Maimane told journalists on Monday.

The party is expected to file an application on Wednesday or Thursday, citing Zuma and the presiding officers of the National Assembly as parties, federal council chairperson James Selfe said.

Chief whip John Steenhuisen said the DA would also file a motion of no confidence in Deputy Speaker Lechesa Tsenoli, who chaired the session at the time.

The chairperson or speaker is constitutionally bound to hold the executive to account during question sessions, Steenhuisen said.

"The deputy speaker did nothing of the sort. He completely abdicated his responsibility in the most cowardly way possible."

He added that there was no good reason for Zuma to arrive at Parliament without an answer, nor any good reason for him not to be compelled, by the deputy speaker, to answer.

Parliament has been turned into another one of the "President's Keepers", he said.

'Setting a precedent'

The courts have traditionally veered away from interfering with the way Parliament conducts its business, due to the separation of powers.

However, Maimane said the spy tapes case was costly for the party and for taxpayers, and that citizens had a right to know how much it had cost.

"This was the most expensive case we fought. We fought hard, tooth and nail, and asked South Africans to assist with funding it."

Zuma, on the other hand, had access to state funds to fight the case, he said.

Selfe said Zuma must be personally liable for the costs. He wasted the court's time by withdrawing his application in the end, after a seven-year battle.

Ultimately, it was not just about Zuma, Maimane said.

"It's about the office of the president. If we allow this to stand, another president could effectively come to Parliament, read a magazine and that could be a legitimate answer."

For this reason, the party has to fight it now, he finished.