Mmusi Maimane's former chief of staff in the DA has quit from his position in the party.Graham Charters, who remained chief of staff in the federal leader's office after Maimane's exit, announced his decision on Thursday.John Steenhuisen has replaced Maimane, but only as interim federal leader. The DA will elect a new leader in April.READ | Maimane says he does not hate Steenhuisen, despite calling him JudasNews24 has seen a letter, dated February 6, 2020, which Charters sent to Steenhuisen and three other officials.In the letter, Charters states that he is resigning as chief of staff and as a "DA staff member".He also expresses his gratitude "for the opportunity to work in the Leader's Office for the past four years".Charters made his decision public on Twitter."I have today tendered my resignation as Chief of Staff to the DA Leader with immediate effect. This has not been an easy decision to arrive at, but after much thought, prayer and discussion with friends and family, Siya and I are convinced it is the right decision," Charters posted to Twitter.The last 6 years as a DA staff member has been an incredible adventure, making history along the way, but sadly this chapter has come to an end. (2/2)— Graham Charters (@Graham7Charters) February 6, 2020When News24 asked him why he had resigned, Charters he needed a "new challenge".'No personalities in DA were a factor'"The new DA leader deserves to form his/her team with individual aligned to their vision for the party and the country. No personalities in the DA were a factor," he wrote in a reply to questions about his decision.Charters, whose wedding was officiated over by Maimane, said he was not sure what he would be doing in future.A Twitter love story: He sent her a DM, she responded, they fell in love and former DA leader Mmusi Maimane officiated at their wedding | @W24_SA https://t.co/99LtPNl1Bz pic.twitter.com/Vebgnwmecp— News24 (@News24) December 30, 2019 "My wife and I have been married for just one month, so this allows us to take some much needed time to plan our next move. But whatever our next move may be, we will always be guided by how we can play our part in building a multiracial South Africa that is fair, reconciled and truly belongs to all."READ | Mbali Ntuli eyes DA top job: 'If we don't save the DA, we cannot save SA'Charters' resignation comes just over a week after Mabine Seabe, another staffer who was close to Maimane during his time at the helm of the DA, announced his departure from the party.Seabe, who was once Maimane's spokesperson, resigned as acting director of communications last Tuesday."For the record, I resigned on my own terms. I am working on an exciting venture with some talented people to change how the private sector communicates and channels its CSI funding. I wish my former colleagues all the very best," Seabe tweeted on the day he announced his resignation.