DA MP Gavin Davis resigned as an MP on Thursday to take up a position as CEO at Resolve Communications, the firm of the party's former leader, Tony Leon.
"This is a great opportunity to lead a successful strategic communications firm into its next phase of growth," Davis told News24.
"I am particularly excited to be working with Tony Leon, one of the great political minds of our time."
Davis was one of the DA's outspoken proponents of liberalism and ahead of the party's conference, he co-authored a paper along with his colleague Michael Cardo, arguing against the use of race-based quotas in the DA's policies. In the end, the DA rejected quotas.
Asked if the current debate within the DA about liberal principles played a role in his decision, Davis said: "Not at all. I enjoyed playing a role in these important debates. One of the great things about the DA is that there is space for robust debate in which each individual can voice their opinion without fear or favour."
After becoming an MP in 2014, he served on the Portfolio Committee on Communications, where he played a role in the removal of Ellen Tshabalala as chairperson of the SABC board after she had lied about her qualifications, and also tackled then communications minister Faith Muthambi and former SABC COO Hlaudi Motsoeneng head on.
He passed that baton to Phumzile van Damme when he moved to the basic education portfolio.
After that, he served as the DA's policy head, before moving to the energy portfolio.
"I really enjoyed my work on the various portfolio committees that I served on. People don't often realise that, away from the adversarial plenary debates, there is a great deal of co-operation across party lines," he said.
"We held people like Hlaudi Motsoeneng, Faith Muthambi, Ellen Tshabalala and the Guptas to account precisely because members of all parties were able to put their political differences aside.
"Another highlight was working closely with [DA leader] Mmusi Maimane on some of the big speeches he delivered in Parliament. The 'Broken Man' speech, for example, helped turn the tide against [former] president Zuma and the project of state capture. It was one of the rare instances when a speech in Parliament made a real difference outside Parliament."
Davis was previously the DA's communications head and has a master's degree in politics.
Resolve Communications courted controversy earlier this year when it was revealed that it got a contract of R658 000 to deliver "strategic advice" to improve the City of Cape Town's drought crisis communication. The company and City maintained the contract was above board.