Button will be racing alongside the man he displaced as champion, and it will be the first time a team has fielded two World Champions as teammates since 1989, when McLaren had a line-up of Ayrton Senna and Alain Prost.

Button is expected to receive double his previous salary at McLaren, from £4 million a year at Brawn to £8 million a year. The Brit admitted that leaving Brawn GP was a "difficult decision", but said, "Life is about challenges. Most important of all, it's about challenging yourself."

He added, "Although I won the World Championship with Brawn GP last year, and I'll never forget that, I was always adamant that I wanted to continue to set myself fresh challenges. That's why I've decided to join Vodafone McLaren Mercedes. You can't help but be affected by this team's phenomenal history."