Democratic Alliance leader Helen Zille said on Sunday it was still unclear whether she would remain as mayor of Cape Town, take a seat in parliament or become premier of the Western Cape after the elections.

"I have three options," Zille said as she unveiled her party's nominations lists for the National Assembly and provincial legislatures.

"I can stay in Cape Town, come to the National Assembly or go to a province. We are still going through the process and even I cannot pre-empt that process," she said.

Zille introduced academic and former head of the Immigration Advisory Board of South Africa Wilmot James, DA spokeswoman Lindiwe Mazibuko, prominent radio personality Niekie van der Berg, former AgriSA boss Lourie Bosman and Makhosazana Mdladlose, daughter of Frank Mdladlose, co-founder of the Inkatha Freedom Party as candidates for the National Assembly.

James is number two on the party's Western Cape National Assembly list, behind DA chief executive officer Ryan Coetzee, who was catapulted into parliament by former DA leader Tony Leon in the last elections.

James said he resigned as a trustee of the Ford Foundation of New York to answer the call of politics.

"I am enthusiastic about and committed to the values exemplified by the Democratic Alliance in terms of freedom under the law, the separation of powers and the commitment to excellence in education," he said.

"We need to pass good laws to build this country."

Mazibuko said she was delighted to be able to stand for parliament for the DA at a time when politics could at last transcend identity.

Bosman, who tops the party's Mpumalanga list for the National Assembly, said he would fight to reverse the agricultural policies of the African National Congress which had wrongly turned South Africa into a country unable to grow enough food for its people.

"The ANC made the big mistake of turning a net exporter of food into a net importer so that we are now unable to provide for ourselves."

Mdladlose has defected from the tiny opposition party Nadeco, for whom she was an MP, to join the DA.

Zille said she was delighted to welcome a host of new candidates into the party ahead of the upcoming polls.

"These are only some of our new colleagues. There will be many more. This is going to be the start of a challenging, rewarding but arduous career."

The DA suffered a heavy blow last month when its parliamentary leader Sandra Botha resigned to take up the post of South African ambassador to Prague.

Zille kissed Botha and wished her well but Van der Berg, who is number five on the Gauteng National Assembly list, chided her for leaving the party in the lurch.

"I'm sorry you dropped us," he said.

The DA has seen a minor exodus of senior members recently as people retired or chose to pursue different careers.