Red Bull motorsport advisor Helmut Marko has ruled out the company showing any interest in Formula E in the future.

The all-electric series has been growing in stature since its inception in 2014 and now, in Season 5, has attracted a number of major carmakers and boasts a strong grid of drivers including multiple former Formula 1 stars.

However, Red Bull, who sponsor racers in a number of categories and have recently expressed an interest in Le Mans from 2021, aren't impressed by what they see.

"We're racing purists," Marko told Motorsport.com. "As good as we are in marketing, Formula E is for us only a marketing excuse from the automotive industry to distract from the diesel scandal.

"The bottom line is that diesel is by far the most efficient engine."

Manufacturers like BMW, Audi, Nissan and Jaguar all currently compete with Porsche and F1 champions Mercedes joining from Season 6.

And having seen what has happened to the price of racing in F1 as a result of manufacturer dominance, Marko warns a similar trend will start in Formula E.

"In the beginning, the costs were eight million. Now it's well over 20. If the really big ones like Porsche and Mercedes come, it will go up again," he said.

Also Read:

• Villeneuve dismissive of Formula E: Nobody in F1 knows when it's on!
• Hamilton praises Formula E project but rules out becoming an 'electric-head'

The Red Bull advisor's main critique, however, is the current spectacle Formula E provides.

"The Formula E cars are like a Formula 3 car with a 400kg battery," he added. "It is not about being the fastest driver as it involves a lot more energy management than in F1 or in any other racing series.

"They are so slow. It only looks attractive on these tight and twisty city circuits."

That is why Marko believes Formula E is nothing more than a marketing ploy.

"The huge advantage is that Formula E is a super marketing gag, in the middle of the cities," he said. Ask your girlfriend if she wants to go to Spa-Francorchamps or to New York! That's the basic concept of Formula E, to go to the people.

"But there is hardly any public image generated through TV. Only one can win and when the budgets then go towards 40, 50 million, at least one [manufacturer] will only be fifth or sixth.

"[When that happens] I believe that the euphoria will be gone quickly."