Jenson Button has said that he does not expect McLaren to have the pace to compete for a win at the Spanish Grand Prix this weekend.

The Woking-based outfit have struggled to match the leading teams in the first four races of the 2013 Formula 1 season, but have brought a series of upgrades to the first European race of the calendar.

The 2009 world champion told reporters: "It's great that we're able to turn things around so quickly in terms of bringing parts to the circuit, but we're still a hell of a long way off the pace.

"There are some positives to the parts, but some areas we need to improve on - areas I didn't think we would have to. We haven't slipped back, we've made improvements but I think everyone has.

"The important thing is that the correlation much better now, which is a positive, definitely for the future. I think [on Sunday] you'll see four teams that are very competitive at the front. I don't think we'll be one of them but I think we'll be just behind hopefully."

The Briton, who is 10th in the drivers' standings, set the 12th-fastest time in this afternoon's practice session.