Red Bull Formula 1 technical chief Adrian Newey says it "would have felt wrong" to leave the team despite being approached by Ferrari with an "incredible offer" inn 2014.

Newey stands out as one of the most successful car designers in F1 history, enjoying success with Williams, McLaren and, most recently, Red Bull, helping its march to four straight championship doubles between 2010 and 2013.

Newey was approached by Ferrari to join as its new technical boss in 2014, but opted to take up a revised role at Red Bull that allowed him to explore projects outside of F1, including a new road car designed in collaboration with Aston Martin.

Speaking to Sky Sports, Newey revealed he has received three serious offers from Ferrari through his motorsport career, but did not feel comfortable leaving Red Bull when the most recent approach was made four years ago despite the team's struggles.

"It became evident that the [Red Bull engine supplier] Renault was a long way behind the Mercedes in particular and to some extent the Ferrari - with no obvious end in sight," Newey said.

"Renault didn't seem to be willing to put the funding in to really sort the problem out, which was the depressing and worrying bit.

"I was in a bit of a difficult position. I didn't want to walk out of Red Bull because it feels like home and I'd been heavily involved from the start with Christian [Horner, team principal], building the team up from the ashes of Jaguar to where it was today.

"I didn't want to walk out on that but equally I didn't want to be in a position where we were operating with one hand tied behind our back in the engine department.

"It was a very difficult decision. Ferrari came up with an incredible offer, very attractive, and it caused me a lot of sleepless nights deciding what to do and who to go for.

"In the end, it would have felt wrong to walk out on Red Bull."