Lack of tow cost Jenson Button F1 Q3 spot in Canadian GP qualifying

The McLaren-Honda driver was in contention for 10th pace in the dying seconds of Q2, but that spot went to team-mate Fernando Alonso and Button ended up 12th.

Although he had a minor lock-up into the hairpin (pictured), Button said it was the lack of tow that explained his deficit to Alonso 0.177s in Q2.

"I locked up every lap at the hairpin and actually went quicker there on my final lap," said Button.

"It was on the straight that I lost out compared to Fernando - he got a very good tow off me and gained almost two-tenths in the last sector.

"Up until the last sector, it was looking pretty good for P10 but then I lost out because I didn't get the tow."

Button, who also slipped behind Force India driver Sergio Perez, believes he can fight for points in a dry race - aided by having a free choice of which Pirelli tyre compound to start on.

But he also suspects tomorrow's race will be hit by rain, giving him and McLaren a chance to punch above their weight.

"We can choose our tyres and 10th or 12th doesn't really make a lot of difference if it's wet anyway," said Button.

"In those mixed conditions it always makes it a bit more fun, it's not just the quickest cars that are near the front and you can mix it up a bit if you get the strategy right and they don't."

Alonso admitted he was surprised McLaren was this competitive in Canada.

But he warned the car's lack of straightline speed could prove a big weakness in the race.

"It was a nice surprise, at this circuit we didn't expect to be in Q3 in front of one Force India and four-tenths off the Ferraris in Q2," said Alonso.

"The race will be difficult, quite tough for us [because of] the very long straights here.

"We are lacking a bit of straightline speed with a lot of fuel saving to do."