Johannesburg - The DA's federal chairperson, James Selfe, has declined a request by party leader Helen Zille to stand as candidate for the party's caucus leader in Parliament.
"I thought long and hard about it. I decided it is not a good idea because I have another important job I do," he said on Sunday.
Selfe said Zille asked him if he was available to stand for the position last week.
Selfe would not comment on whether he thought the party's national spokesperson Mmusi Maimane would be a good candidate for the position.
"I would have to wait to see who else was available."
Selfe said the Democratic Alliance was "spoilt for choice".
On 11 May, EyeWitness News reported that Maimane had accepted a seat in the National Assembly. He said elections for the party's parliamentary leader position were a separate matter.
"What is absolutely critical is that fact that I stand as an MP, which is the only role I have at the moment and no other decisions or further conversations have been entered into," he was quoted as saying.
Lindiwe Mazibuko was elected the party's parliamentary leader in 2011, beating Athol Trollip by 50 votes to 31. This made Mazibuko the youngest MP, at 31, to lead a party in Parliament and the first black woman to do so.
Mazibuko announced last weekend that she would quit her position to study at Harvard University in the United States.
"I took the decision in September when, during a visit to Yale University with others pursuing high-profile careers, the value of such a break became clear to me.
"I had considered it before, and I believe the decision is the right thing at the right time for the DA and for me because it will improve what I can offer the DA politically," Mazibuko told the Sunday Times at the time.