Jenson Button believes his title defence will be the most difficult in the history of Formula One.

The 29-year-old Frome driver, who sealed his maiden crown last weekend at the Brazilian Grand Prix, said: "It's getting more and more difficult. It's a very competitive sport. For me, every single driver on the grid deserves to be there. It's amazing how close it's been this season.

"You always want more and achieving the world championships is a great feeling and I'll enjoy that for many more days but after that life goes on and you want to achieve greater things. That will be the aim."