MONTREAL, Canada - McLaren's Jenson button, given his team's dismal performance at the 2013 Canadian Formula 1 GP, has written off the 2013 championship.Button said after failing to score points in Montreal that, seven races into the troubled development of the MP4-28, the gap to the leading teams remained "massive".‘WE CAN STILL WIN GP'S’Button said: "We're so far behind, we're never going to win the championship in 2013."With 12 races, Button is already more than 100 points behind in the Drivers' championship. The obvious temptation for a heavily-resourced team such as McLaren would be to switch all of its focus to the radical new regulations and a new V6 car for 2014.Button suggested McLaren was determined to improve in 2013: "We can still win GP's." He ruled out earning a podium place for his home British GP at Silverstone on June 30 2013.As for how long the slump might last, Button admitted: "Nobody knows the answer to that. It's pointless for me to try to answer."