Electric racing series Formula E will be more popular than Formula 1 in five years, according to Virgin Racing chief Sir Richard Branson.
The 64-year-old ran an F1 team in 2010, and backs the Virgin Racing team in Formula E.
He said: "I think in four or five years you will find Formula E taking over from F1 in terms of number of people.
"As time goes on, the clean energy type of business will power ahead of other businesses."
British entrepreneur Branson was speaking at Battersea Park which hosts the final rounds of the inaugural Formula E season.
He also said that 20 years from now "no new road cars will be petrol driven", adding that the current technology was "antiquated".
Formula E, which is backed by motorsport's governing body, the FIA, is the first ever single-seater electric car-racing series.
In-race music, social media influencing the outcome and Leonardo DiCaprio - your guide to Formula E.
It was created to attract a new audience to motorsport and to help develop electric vehicle technology.
FIA chief Jean Todt, who was present at the same news conference, told BBC Sport he believes both competitions can live side-by-side.
"It's the same family. I hope Formula E becomes bigger. It's a nonsense to think they are competing against each other," said the Frenchman.
And in response to recent criticisms over the future of F1, Todt added: "F1 is fascinating, I'm wondering why there is such negativity around it. Where is the passion to make it better?"
The 64-year-old ran an F1 team in 2010, and backs the Virgin Racing team in Formula E.
He said: "I think in four or five years you will find Formula E taking over from F1 in terms of number of people.
"As time goes on, the clean energy type of business will power ahead of other businesses."
British entrepreneur Branson was speaking at Battersea Park which hosts the final rounds of the inaugural Formula E season.
He also said that 20 years from now "no new road cars will be petrol driven", adding that the current technology was "antiquated".
Formula E, which is backed by motorsport's governing body, the FIA, is the first ever single-seater electric car-racing series.
In-race music, social media influencing the outcome and Leonardo DiCaprio - your guide to Formula E.
It was created to attract a new audience to motorsport and to help develop electric vehicle technology.
FIA chief Jean Todt, who was present at the same news conference, told BBC Sport he believes both competitions can live side-by-side.
"It's the same family. I hope Formula E becomes bigger. It's a nonsense to think they are competing against each other," said the Frenchman.
And in response to recent criticisms over the future of F1, Todt added: "F1 is fascinating, I'm wondering why there is such negativity around it. Where is the passion to make it better?"
