Lewis Hamilton has denied that his decision to switch teams from McLaren to Mercedes was for financial reasons. The British driver, speaking for the first time since signing a three-year deal with Mercedes that starts next season, was open about the challenge he faces with the German team but also said that he felt the split with McLaren was amicable and did not rule out a possible return to the team some time in the future.

Speaking in Tokyo, ahead of Sunday's Japanese Grand Prix at Suzuka, a relaxed Hamilton was happy to talk about the move. He will replace the seven-times world champion Michael Schumacher at Mercedes but, while previously tight-lipped during negotiations, he has now revealed that his choice to leave the team was no easy task.

"It was hard. Really, really hard. It was very, very stressful and then there became a crunch time where there was pressure from the team. I had a couple of deadlines, I didn't meet any one of them. There was one deadline and we didn't do anything with it. We just went on to another deadline. But then the decision was made. It really, really was tough but once I made the decision I was so much more relaxed."

The question of whether McLaren and their team principal, Martin Whitmarsh, were not willing to match Mercedes in salary terms, widely assumed to be a central bone of contention, was rejected by Hamilton, who asserted that money was not an issue in his decision.

"It was not about the offer," he said. "I had two offers on the table which were very, very similar. Martin asked me what more they could have done. I said: 'To be honest, Martin, it was about the new challenge and a step that I wanted to make.'"

He insisted this step was a considerable personal wrench, moving from a team with whom he has grown up and unsurprisingly has an emotional connection that will not be easily forgotten. "I had to try and separate my emotions from the decision but it was very difficult to do," he said.

"I have got nothing but love for Martin. When you are with a team for so long you generally learn to love them. I think I will always have McLaren at heart even when I am driving for another team down the line. I will still have a bit of my heart that is McLaren."

The driver also reflected on what the move meant in terms of his personal development, above and beyond the expected possibilities for increasing his commercial potential that were widely seen to be limited within McLaren's corporate structure.

"I just know that everyone has to experience those things, working with new people and new environments," he said. "That is just part of growing. It's my last step of independence I guess."

In racing terms the most important part of that step is, of course, the question of whether Mercedes can give him a winning car. It seems unthinkable that he would have made the decision without some strong assurances of future improvements from the team principal, Ross Brawn.

While acknowledging that both next year's car and the current iteration (which scored the team's only win of their three-year existence) were unlikely to challenge McLaren, he was confident that the silver arrows would deliver success.

Brawn does have a superlative track record in building a race-winning team, proven during his time with Schumacher both at Benetton and when the pair brought Ferrari back to dominance in F1.

"I enjoy the challenge there – trying to develop the car," Hamilton said. "It was about Mercedes, a team which has not been that successful over the last couple of years but I know from past experience with them that they want to win. I know some of the greats have gone from a great car to not such a great car and have helped to develop a winning team. Michael [Schumacher], for instance, went from being a world champion to Ferrari. We haven't really got any other driver in Formula One who is known for that. To have that as a challenge … If that does happen, that would be amazing."

Indeed it would be, and something that fans would no doubt love to see, not just because it is, after all, a German team actually based in Brackley, Northamptonshire, but because for Hamilton to do so would be an extraordinary justification of his decision. He also said that regardless of what happens his move does not mean, for him at least, that driving for McLaren again is out of the question.

"We have an incredible relationship and I don't feel as though I am going out of McLaren through the back door," he said. "I am going out the front door happily. The way I look at it is that I am walking over that bridge and down a different path. If that path brings me back – then who knows?"