Ross Brawn says he is confident that Mercedes will show improved race pace in the Spanish Grand Prix next weekend although he had warned that there is still work to be done to allow Lewis Hamilton and Nico Rosberg to fight for victories.

Both have shown strong qualifying pace thus far in 2013, with Mercedes going into the opening race of the European season on the back of successive pole positions in China and Bahrain.

However, neither driver has been able to convert pole into victory this season, with both Hamilton and Rosberg being unable to match their qualifying performances over a race distance.

Speaking ahead of next weekend's race in Barcelona, Brawn insisted that Mercedes had been working hard to extract more race pace from the F1 W04 but said the team 'wasn't there yet' ahead of the start of the European season.

"There has been a lot of hard work taking place in Brackley and Brixworth to prepare for the start of the European season in Barcelona next weekend," he said. "We have focused our efforts in two key areas; finalising our upgrade package for Spain and understanding our comparative lack of race pace in Bahrain. We have made progress in the latter area and will evaluate some developments over the upcoming race weekends to help improve the situation. We're not there yet but we are making progress and of course, performing in the race is what really counts."

Mercedes enjoyed a solid showing at Catalunya during pre-season testing and despite the different conditions that are expected for the race, Rosberg said he was hopeful of a strong weekend.

"I'm looking forward to travelling to Spain next weekend," he said. "We know that the car went very well at the Circuit de Catalunya in pre-season testing so I am hopeful that we can have a strong weekend. We will have to wait and see how our pace compares however.

"I've been in the factory for a couple of days this week, on the simulator and meeting with the team, and everyone has been working hard to make progress on our race day performance. It will be an interesting weekend and once we see how everyone performs in Barcelona, it should give a good idea of how the rest of the season will look."