Red Bull chief designer Adrian Newey has revealed that he turned down an offer to join Mercedes in 2014.
Newey told the BBC that he had been approached by both Mercedes and Ferrari after Red Bull's fortunes abruptly waned following their fourth constructors title the year before.
“We had this change in engine regulations in for the 2014 season," Newey recalled. "We’d ended up with this situation where we have a big disparity in power unit performance.
"With our particular engine supplier we seemed a bit doomed," he continued. "I got quite depressed about that."
Sensing that Newey might be receptive to offers, Red Bull's rivals made contact to see if they could persuade him to jump ship.
"Ferrari approached [me] as did another team - Mercedes," he revealed. "And it’s kind of make your mind up time."
Newey had joined Red Bull in 2006, having previously played a key role in taking both Williams and McLaren to title success. He said that having been a part of Red Bull from so early on was a big factor in his decision to stay put.
"I guess Red Bull, having built it up from nothing, I felt a paternal bond to the team," he said. "To the people that worked there. I enjoyed a very close and strong relationship with [team principal] Christian Horner."
He said that as a result, the idea of leaving Red Bull "kind of felt like walking out on a family."
Newey's disillusionment with the sport's engine regulations meant he spent time working on projects outside Formula 1. To this day, he's still unhappy about the technical direction of the sport.
"The new hybrids, which I think have not in truth done the sport any favours," he said. "It’s a bad thing.
"I think we’ve been lucky this year. We’ve ended up with two teams - Mercedes and Ferrari - battling for the championship," he pointed out.
"But it’s been the first time in the hybrid era we’ve had two times fighting for the world championship."