Lewis Hamilton casts fresh doubt on F1 future

Lewis Hamilton may have won the British Grand Prix, but he has cast his future into doubt by dropping another hint that he could walk away from Formula One at the end of the season.

Hamilton, who toasted his fourth consecutive victory on home soil by performing his now customary crowd-surfing celebration with his army of British supporters at Silverstone, has moved to within just one point of Sebastian Vettel in the race for the title.