Former F1 boss Bernie Ecclestone says he would be concerned by the rise of Formula E if he was still in the role which he is most famous for.
Ecclestone took control of the series in the 1970s and held a position of power until Liberty Media's takeover in 2017, which saw him given the honorary role of chairman emeritus. The Brit was a critic of the existing V6 hybrid engines, which have been controversial, and last year suggested F1 considered going electric in order to stay in line with direction being taken by the motor industry.
His view has changed over the last 12 months and he now thinks the all-electric series, which is currently in its fourth season, is on an impressive upwards trajectory.
"It's a different form of entertainment but Formula E will begin to get much, much bigger and better, which is slowly what they are doing anyway," Ecclestone told Reuters. "And Formula One will suffer because of that. But I'd be a little bit concerned about Formula E for sure."
When asked which he would consider to be the better business proposition right now, he said: "I think I'd have to say Formula E. There's more chance there of big, big expansion and more chances commercially than there is of changing things in Formula One."
Despite being shuffled out of a position of influence Ecclestone still keeps a close eye on what is happening in F1. Ahead of the current season he predicted predicted Ferrari driver Sebastian Vettel would win the 2019 world championship.
Vettel spun while running in a promising position at the Bahrain Grand Prix, a weekend which saw him unable to match the pace of impressive young teammate Charles Leclerc. Despite that disappointing performance Ecclestone is not ready to revise his prediction just yet.
"I thought he was going to win easy. I (still) think he's going to win. But not easy."