Formula E chief executive Jamie Reigle says he is "flattered" by criticism of the all-electric championship from Formula 1 boss Chase Carey and Red Bull adviser Helmut Marko.

Marko recently told Autosport that Red Bull had no interest in entering FE "because we are racing purists" and it "does not fit" with the brand's promotional activities.

"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," he added.

Days later, Carey, the CEO of F1, was asked during an interview with CNN whether the FE championship posed a threat to F1's popularity and media profile. He replied: "No. Actually, I think Formula E is a very different vehicle…largely a social cause and, you know, more of a street party."

At a 'Future Forum' hosted by BMW in Vienna on the weekend, Reigle responded by citing manufacturer interest in FE and the competitive nature of its races.

"I think the important word in Marko's statement is 'purists'", he said. "There's a definition of what motor racing was and therefore, to people who have that view, of what it should be. In my mind, the beauty of motor racing is that it is this tradition of sport and technical innovation.

"The technical innovations that came years ago were things like rearview mirrors and seat belts. We believe we're pushing the edge of it and fundamentally, if you look at the number of manufacturers coming into FE, the drivers, how competitive it is, the fact that most races we have there's a different winner ... to me that is the definition of sport.

"It's the pinnacle of human endeavor, whether that's engineering or the sporting side and how you bring that together."

As for Carey's dismissive comment, Reigle added: "My personal opinion is that the world is a very big place and there's plenty of room for multiple championships in motorsport.

"It's flattering that Chase and Marko decided they should talk about us."

The 76-year-old Marko is not shy about voicing controversial opinions. In March, he admitted that he wanted Red Bull drivers to deliberately contract the coronavirus before the start of the F1 season.

He said his idea was to bring the team's senior drivers, Max Verstappen and Alexander Albon, together with the junior drivers in a training camp.

"Of course it would've been ideal for the infection to come. They are all young, strong men in good health," Marko told Austrian television channel ORF. "Then you would be prepared for whenever you start, and you'd be ready for a very tough world championship."

Marko has since conceded his plan was "not well received".

Formula E resumes racing on Aug 5 in Berlin, with six races in nine days across three circuit layouts to decide the championship.

Each pair of races will be run on a different layout, and rounds six and seven on the Tempelhof course will be contested clockwise, or in reverse－a first for an international circuit championship.

Adaptations will be made on the ground in the 24-hour period between the first and second pair of races with run-off, curbs, barriers and broadcast placements all subject to being changed on the fly.

"This is a huge undertaking in terms of production to set up three different configurations for this event, with fewer people on site to be able to carry out those changes," said Formula E sporting director Frederic Espinos.

"We're doing something that has never been seen before in world-class motorsport and it's an example of how reactive and innovative Formula E is－it's in our DNA."