Lotus team principal Eric Boullier is confident that his team is still able to compete at the front of the grid despite disappointing performances in Monaco and Montreal.
Lotus started the season well with a Kimi Raikkonen winning in Australia as well as claiming four other podiums, including the race in Bahrain where both drivers finished in the top three.
However, in the last two races the Enstone team only scored three points, although their disappointing Monaco campaign was compounded by an incident between Raikkonen and Sergio Perez, which has seen the team drop below Mercedes in the Constructor's Championship into fourth place.
"We have lost positions, so we have to work hard to keep the pace because the car is competitive, the team is competitive and there is no reason we cannot be back and fighting for podiums," Boullier said.
"We didn't have five podiums at the start of the season just by chance. It is because the package is competitive - we may struggle sometimes on some tracks, but we know this now and we have to work on this now to avoid this happening again this season on low-energy tracks.
"We have to make a step forward - we have some developments coming for Silverstone, so that should help to close the gap to the leaders."