Adrian Newey breaks his silence over contract row

But when he changed his mind and decided to remain at McLaren, Jaguar still put out a statement saying the move was on. Sources insist Newey does not have a contract with Jaguar, only a letter of intent to switch camps, which is less binding.

McLaren and Jaguar are now squaring up for a bitter legal High Court battle for Newey's services because of his staggering record of success. His cars have won six drivers' and six constructors' championships since 1992, also making Jacques Villeneuve, Alain Prost and Mika Hakkinen champion.

As the issue becomes increasingly acrimonious, Newey revealed his abiding concern is for his friendship with Rahal, whom he has known since working as his engineer nearly 15 years ago.

"One of the reasons I made this decision was because I was enthused about the idea of working with Bobby again," said Newey. "Maybe that persuaded me to go down a road that I might not have gone down in different circumstances.

"But on reflection, shortly after agreeing to join Jaguar there was a realisation that changing teams was not the way to go for me.

"I had previously agreed with Jaguar that nothing would come out until 8.30am on Friday morning. When I spoke to them and informed them of my decision they agreed to stop the press release being issued. At that point, only a few people were affected. Despite that it appears they chose to issue the press release.

"The person I am concerned about in all this is Bobby. He is a good friend and I don't want to upset him. Perhaps this shows the dangers of mixing a friendship with business. I really hope our friendship can weather this."

Newey also revealed another reason for his decision to switch teams was his desire to seek new inspiration in the pressure-cooker environment of Formula 1 design, as he is threatened with burn-out. He quickly realised the move to F1 newboys Jaguar would not lead to more inspiration - only more pressure.

"I am a designer and like anyone in my situation I am trying to be creative and to do that you look for new stimulation," he said. "There is always a danger of getting tired and suffering something equivalent to writer's block and wondering where the next little bit to improve the car, the next idea, is coming from.

"This is a high pressure sport and I have been working in it a long time. With that constant pressure you are looking for a new stimulus and changing jobs is one way of doing that. It is not exclusive to Formula 1 - city whizz kids do it all the time."

Newey has been linked with McLaren's plans to design an Americas Cup yacht.

"I can't comment on what the future might hold for me," he said. "But I have made up my mind and I want to stay at McLaren now."