Speculation had surfaced that Brawn was on his way out of the Brackley-based team after parent company Daimler opted for a reorganisation of their Formula One activities.
Toto Wolff, formerly an executive director with Williams, is to take on the same position with Mercedes-Benz Grand Prix Ltd after signing a letter of intent to acquire a significant minority interest in the company.
In addition, former three-time Formula One world champion Niki Lauda, who is currently non-executive chairman of MGP, will also acquire a stake in the company.
Despite the rumours, and on the day Lewis Hamilton addressed the workforce in Brackley for the first time, Brawn was adamant there would be no question as to who holds the reins.
"Toto is coming in and there is another side of the business that quite frankly I don't want to get involved in," Brawn said.
"I don't want to get involved in the commercial activities and with the support we need to give Daimler on a day-to-day basis.
"There are a lot of things Toto will be doing which are complementary to what I am doing in terms of running the team.
"But you have to have one reference. Everybody knows the only way a racing team will work is to have one reference, and I'm that reference.
"I am the team principal and I am in charge of sporting, technical and racing matters."
Hamilton, meanwhile, confirmed he had been reassured by Brawn about the 58-year-old's future role in the team.
"I don't read all the stories that come out, but if I've any problems or I do hear any whispers then I can give him a call, which I did and he set me straight right away," Hamilton said.
"We already have that kind of good relationship. We have had a respectable relationship for some time now.
"Over the last couple of months we have built a good, open relationship.
"From the beginning I said I'll always be blunt. It's important we have an open relationship. That's the way best way to start and he was positive about that."