Audi Sport Formula E driver Lucas di Grassi has hit back at Helmut Marko following the Red Bull motorsport boss' heavy criticism of Formula E.
Marko said that Red Bull, as "racing purists", would never be inclined to enter a series that is nothing more, in his view, than "a marketing excuse from the automotive industry to distract from the diesel scandal".
Formula E is currently enjoying healthy growth, thanks to the involvement of a multitude of major manufacturers like Audi, BMW, Mercedes and Porsche.
And that presence precisely validates the all-electric series as an interesting development ground for new technology says di Grassi.
"Audi gains more here in Formula E than in Formula 1," di Grassi told Motorsport.com.
"The fact is that every car of Audi in the future will be electric, and we need to understand which factors are limiting us, which are the bests materials and how to develop software to control the engine.
"We have all this development of the electric car that will be used in the future.
"[With] the combustion engine you already know how it works. The interesting thing is discovering how we can make electric cars run fast, [be] more efficient and more cheap.
"This is what we do here. Not only Audi, but everyone. So, this is much more of a commercial development than Formula 1."
Di Grassi, who was crowned Formula E champion in 2017, also took exception with the "purists" label attributed by Marko to Red Bull.
"Dr Marko said that he is a 'racing purist'. For me it is an argument [that is] a bit false, because it depends a lot from what this means for people," added the Brazilian.
"What exactly is this thought? [Does he] defend races with horses instead of cars?
"If he is a real racing purist, he should defend horse races. Or races with just combustion engines, without hybrid systems as F1 is nowadays.
"Or cars with full manual gearboxes, without paddleshift, [which is] how it is nowadays in F1 – it is an open argument.
"This is more his personal opinion of saying: 'look, I don't want to compete in Formula E, I'm too old for this and want to do combustion races in F1'.
"F1 is still the most important category of the world of motorsport, nobody can deny this. But the future of the manufacturers is electric."