Bernie Ecclestone has admitted that, mere weeks ago, this weekend’s inaugural Korean grand prix risked not going ahead.

The F1 chief executive recently expressed doubt about the incomplete Yeongam venue, which has now been passed fit by the FIA to host the formula one circus.

“It’s done now,” Ecclestone said in an interview with the Guardian newspaper.

“Last month I didn’t think it would be finished. And it would have been cancelled then — for sure.”

But the Briton, to turn 80 later this month, defended his campaign of the last decade or so to expand the sport far beyond its traditional European base.

Since the late 90s, F1 has moved further into Asia and the Middle East, and the likes of India, the USA and Russia will soon also be on the calendar — despite waves of scepticism among some of the sport’s purists.

“In the end common sense has prevailed and we’ve expanded. It’s just having the courage to do it,” said Ecclestone.

A potential problem, however, is that F1′s expansion has put in jeopardy some of the historic, much-loved but outdated venues and hosts — like the popular Spa-Francorchamps.

But is the incredible Belgian venue really in danger of losing its grand prix? “Absolutely,” Ecclestone insisted.

“If it wasn’t supported by the government over there it probably would go because they wouldn’t be able to afford it. It’s the same with the British grand prix,” he added.

Another problem is that the circuits replacing the old guard are mostly penned by Hermann Tilke, who has been accused of churning out bland clones.

“Our problem is that we’re trying to build race circuits that are super safe,” Ecclestone explained. “You don’t get so much up-and-down because you can’t just put a new circuit anywhere.

“But one of the best circuits in the world is Turkey. It’s a great circuit — that’s up-and-down.”

But even the Istanbul venue is in doubt, the Briton revealed, because of efforts to cap the calendar at 20 races.

“Maybe someone will decide they need a rest because it’s not working for them commercially. A good example is probably Turkey,” said Ecclestone.

“They’ve built an incredible circuit and it might even be the best — but there’s not much enthusiasm from the public. I don’t know why.”