Cape Town - The ad hoc committee established by Parliament to consider submissions by President Jacob Zuma in response to the public protector's report on Nkandla must make use of all its powers, the DA said.
"President Zuma and all implicated ministers must be summoned to testify," Democratic Alliance chief whip Watty Watson told reporters at Parliament.
Establishment of the 12-member committee was announced in a statement by Parliament on Wednesday. It will comprise seven African National Congress MPs, two DA MPs, one Congress of the People MP, one Inkatha Freedom Party MP, and one other MP representing the smaller parties.
"The mandate of the ad hoc committee is to consider the submissions by the president in response to the public protector's report and make recommendations where applicable," it said in the announcement, which comes less than a month before the 7 May elections.
The DA welcomed the decision on Wednesday.
INTERACTIVE MAP! Take a look at how the DA fared in the previous elections by clicking here.
Responding to a question, DA federal executive chairman James Selfe conceded that the mandate of the committee could well be limited by the ANC majority, but said the ruling party "would be very silly" to do so.
"That's clearly one of the ways in which the committee can operate. They... can use the parliamentary majority... they can limit the scope of the investigation in any way they wish.
"But they will be doing so in the full glare of publicity and in a situation where people are making political decisions and choices ahead of a general election."
Selfe said it would be "very silly of them to try to appear as if they wished to cover up that which ought not to be covered up".
It would be better to be more open in respect of Public Protector Thuli Madonsela's report on the R246 million security upgrades at Zuma's private Nkandla homestead in KwaZulu-Natal.
"I really think the politics of excluding or limiting the mandate of the ad hoc committee would be a really stupid decision on the part of the majority party," he said.
DA parliamentary leader Lindiwe Mazibuko said she and Selfe would be the DA members serving on the committee, with DA federal chairman Wilmot James in the back-up role of alternate member.
She hailed the establishment of the committee as a victory for Parliament, for the Constitution and for accountability.
The DA is seeking to have Zuma impeached.
Mazibuko said that besides looking for answers to 29 unanswered questions, posed to Zuma by the public protector, "we have a responsibility... as Parliament, [to] make a ruling as to whether or not [the president] is fit to remain in office and whether we should remove him..."
She said the committee's decision would have to be tabled in the National Assembly.
The office of the ANC chief whip on Thursday also welcomed the decision to establish the ad hoc committee.
"The ad hoc committee will restrict itself to its mandate outlined in the points of reference and report back to the National Assembly with recommendations where applicable."
In a statement, it said the committee had nothing to do with impeachment of the president.
"Contrary to the opportunistic, misguided and deliberately misleading electioneering rhetoric from the DA, the ad hoc committee has absolutely nothing to do with either the so-called 'impeachment' or the DA's request for the establishment of a 'committee to impeach' the president."