Eric Boullier says he is now hoping to see Lotus challenge for at least second place in the constructors' championship ahead of the resumption of the F1 season at Spa.

Boullier had set his team a target of third place at the start of the season, with the Enstone-based squad currently fourth going into the second half of the year.

However, Ferrari are just eleven points ahead in third while Mercedes are only 14 points further ahead in second in what seems set to a frantic battle for position - leaving Boullier to feel Lotus still has plenty to play for in the remaining nine races of the year.

"The championship is so close between ourselves, Ferrari and Mercedes at the moment that we really need to be aiming a little higher to make sure our goals are reached," he said. "I think therefore that to target P2 is a better ambition, and we will be pushing harder than ever to sustain that challenge.

"We have an ambitious group of people at Enstone and a top three placing at the end of the year is very much possible, which would be a fantastic achievement for everybody involved. We head into the next nine races on a real high."

Lotus has one win to its name thus far thanks to Raikkonen in Australia, but lost ground in the title race with three tough results in Monaco, Montreal and at Silverstone.

However, having returned to form in the two races before the summer break, Boullier said he was pleased with the way things had gone thus far.

"Overall I'd say it's been a positive start," he said. "There have been a lot of high points, but also perhaps some less satisfying moments. We've taken eight podiums from ten races so far, which is a great achievement for the team and shows that once again we've clearly made a step forwards from the previous year.

"Of course, amongst those highlights we've had three races - Monaco, Montr?al and Silverstone - where we did not score as many points as we should have done, but the important thing is that we recovered from these small blips to challenge for wins at the N?rburgring and also in Budapest.

"For me it's a big positive to show that we have the capability as a team to bounce back and sustain a challenge against opponents with greater resources at their disposal."