By Carien du Plessis

DA whizz kid Ryan Coetzee has resigned as an MP and CEO of his party to become party leader and Western Cape Premier Helen Zille's chief adviser.

Coetzee, who starts his new job on Wednesday, said he made the decision because he was thinking of "what is best for the party and where best can I make an impact".

He said that if he had won the contest against former DA Eastern Cape leader Athol Trollip to become the party's parliamentary leader, he would have stayed on as an MP.

Coetzee said his new appointment came after talks with Zille "over a couple of weeks".

A close ally of Zille's, Coetzee is also regarded as the mastermind behind the DA's vastly improved elections performance this year.

"The issue is what can I do to best help the DA advance its course," he said.

Coetzee said his new job would mainly entail helping the party with its modernisation process and improving service delivery in the province.