But di Grassi, whose Audi squad is among a high number of major manufacturers to commit to FE programmes in recent years, said the technical development opportunities in the series made it extremely attractive.

"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.

" the combustion engine you already know how it works. The interesting thing is discovering how we can make electric cars run fast, 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 also questioned Marko's 'purist' description of Red Bull.

"Dr Marko said that he is a 'racing purist'. For me it is an argument a bit false, because it depends a lot from what this means for people," di Grassi continued.

"What exactly is this thought? 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, 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."