Western Cape Democratic Alliance (DA) leader Bonginkosi Madikizela has taken himself out of the running for Cape Town Mayor Patricia de Lille's post, saying he is already running for Western Cape premier.

Madikizela, who is Western Cape MEC for Human Settlements, was mooted as De Lille's possible replacement at the beginning of the year when the impasse between De Lille and the DA first broke out.

However, he told News24 on Monday evening that he was "definitely not" running.

He has already put forward his name as a candidate for Western Cape premier in the 2019 elections and is "absolutely" focused on his chances to win.

Other premier candidates include MP David Maynier, MEC Alan Winde, Fazloodien Abrahams, Kelly Baloyi, Jacobus MacFarlane and Micheal Mack, the DA announced in July.

As DA provincial head though, Madikizela said provincial leaders would be meeting on Monday to discuss the procedure for finding De Lille's replacement, which involves an internal electoral college process.

The party will soon call for applications from members to replace the mayor after her resignation over the weekend, he said.

De Lille, along with DA party leader, Mmusi Maimane announced her resignation, effective from October 31, on Sunday.

Once applications close, the federal executive will convene the selection panel to interview the candidates. After the interviews, the best candidate will be announced as the replacement.

"We know how we will do it. We will have timeframes regarding opening up applications and so on from next week onwards."

He added that October 31 was "still a long way away" and would leave space for a transition period. The applications were also not restricted to members of the DA's Cape Town caucus.

It would be premature at this point to speculate on who would apply because the news "only broke yesterday," he added.

Meanwhile, De Lille told News24 that she would assist with the transition period. The successful candidate was likely to be in place in council before her departure at the end of October, she added.

Some in the party believe the new candidate should continue to be a coloured mayor, a senior DA member told News24. Coloured people still make up the slight majority of residents in the city and represent a key constituency ahead of the 2019 general elections.

The member was not sure if De Lille would stay on as a regular councillor, but said there were many strong candidates that fit the mould, including Ivan Meyer and Albert Fritz, who are both MECs in the provincial legislature, and current DA metro head Grant Twigg, a councillor in the Cape Town City council.

Whoever the final pick is, the party will have to invest in them to ensure similar popularity levels to De Lille, in the same way it has invested in the likes of Johannesburg Mayor Herman Mashaba, the source added.