Trollip (45) beat DA chief executive and election strategist Ryan Coetzee, who was considered the frontrunner for the job, in a party caucus vote on Thursday.

The caucus decided to retain Ian Davidson as the DA's chief whip.

Trollip, a farmer and fluent Xhosa-speaker whose grandfather was a United Party MP, is a veteran of the Bisho legislature but became a member of Parliament for the first time on Wednesday.

He said he would get "an orientation course" from the more experienced of the party's 67 members of the National Assembly and hinted that under his leadership the DA would opt for a less confrontational approach towards the African National Congress.

"There is room for improvement on how we deal with the governing party from our side and certainly from their side," Trollip told reporters moments after he became parliamentary leader.

The party did not divulge how many votes he drew compared to Coetzee, who was expected to lead a combative charge in the Assembly.

Jacob Zuma held out an olive branch to the opposition on Wednesday after he was formally elected president, promising to do his best to "open a new chapter in relations between government and the opposition".

Trollip said the relationship between president and opposition leader was largely a "matter of personalities" and suggested his relationship with Zuma would differ from that of Tony Leon and former president Thabo Mbeki, who waited years to have a private meeting.

"They had a very difficult, fractious relationship. I will try to make sure we can build bridges."

Trollip insisted however, that the DA still wanted "a competent court" to review the National Prosecuting Authority's decision last month to withdraw corruption and fraud charges against Zuma.

"Zuma has some serious issues to clarify with the courts," he said.

Trollip said the DA would look for common ground with the newest party in the house, the Congress of the People, which has taken 30 seats.

He welcomed Cope's arrival on the political scene as "a fundamentally important" part of the re-alignment of South African politics, adding: "We hope to co-operate closely with them."

He said he looked forward to working closely with DA leader and Western Cape premier Helen Zille. Trollip stood against Zille in the race for party leader in 2007 after Tony Leon quit, but she won comfortably.