Jenson Button mystified by lack of pace in qualifying for the Monaco Grand Prix

Jenson Button believes moving forward in tomorrow's Monaco Grand Prix will be tough after he was mystified by a lack of pace in qualifying

The McLaren driver had been competitive in practice, but failed to make Q3 and will start the race from 12th.

"I didn't make a mistake, it just wasn't quick," admitted the 2009 Monaco victor. "This morning the car felt good and the pace was pretty strong, but we don't have it this afternoon - when it counts."

It is the second race in a row Button has suffered a drop in pace between practice and qualifying, and he is still looking for an answer.

"It's very strange," he added. "It's there at some point in the weekend, even this morning I felt the car was good. We did make some set-up changes, which I thought would have been better, but maybe not.

"It was the same as the last race. In practice the car feels good and then I get to qualifying and I can't find that car.

"The laptime is irrelevant, it's what the car feels like and it felt much better this morning. Hopefully we'll find out the reasons for it."

Despite the unpredictability of F1 in 2012, Button believes progress during the race will be difficult.

"I don't think it's going to be like the rest of the season," he said. "Monaco is all about qualifying.

"Tomorrow is going to be really tough starting where I am. I don't know if the pace will be better in the race and it's very difficult to overtake. "