Button: title defence will be toughest test in F1 history

JENSON BUTTON believes his title defence will be the most difficult in the history of Formula One.

The 29-year-old sealed his maiden crown this weekend at the Brazilian Grand Prix, but it has proved a tough run-in for the Frome racer, who has not won a race since June.

His Brawn GP team only came into existence this season after the withdrawal of Honda from the sport, but their rise to prominence, along with the stern challenge from the Red Bull cars, shows the sport has a depth which reaches far beyond its traditional powerhouses.