Lotus Chairman Gerard Lopez is confident the team will be competitive again in 2015, admitting a design mistake has cost them this season.

The Enstone based team took victory in Australia and a further 13 podiums last year, but in a remarkable downturn in form have scored points on just two occasions in 2014.

Lopez says a fundamental flaw in the design of the E22, as explained by Romain Grosjean at Monza, has cost them and likened the mistake to the forward-facing exhaust concept the team ran in 2011.

“We’ve made a mistake. We’ve made one design mistake that we actually had hoped would help us,” he told the official Formula 1 website.

“We are in the same situation as three years ago when we did the ‘forward exhaust’ and had a terrible season. It’s about the same situation again: we’ve made a choice and it is not paying off - actually it’s the complete contrary. That was a bad choice that translates into a bad season - regardless of the engine. Now the fact that Renault has a number-one team [Red Bull] - and now they officially say it - that is also part of our issue.

“We had a lot of issues at the beginning of the season with the drivetrain and then somehow midway through the season we’ve found out that we have some issues with the chassis, which are quite difficult to solve for this year. But it is good that we found out before we started to develop the next car, so for the rest of the season we try to save whatever can be saved - but yes, it will be a difficult season all the way to the end.”

The Lotus boss refused to comment on whether the team would switch to Mercedes engines next season as per predictions, but he is predicting an immediate return fighting for podiums.

“It was the mistake with the chassis that got us where we are now - and we definitely don’t want to make this mistake again,” he added. “I am not saying that we will be fighting for the world championship next year, but we should go back to where we’ve been the previous two years.”

Lotus announced earlier in this year that Pastor Maldonado would be retained by the team for a second season and Lopez is confident they can persuade Romain Grosjean to stay as well.

“There is a high chance,” he revealed. “One - Pastor - has already been confirmed, and Romain has in his contract - it is no secret that he could step out of the contract given the bad results, but I am pretty sure we will stay with what we have.”

The financial struggles of the team in recent years have been well documented, but Lopez says they are edging closer to turning a profit.

“We are actually publishing the annual accounts and this year we are pretty much breakeven - we eventually could make a profit,” he revealed.

“So I would say that we are one of the best teams financially speaking, so this part is the easiest to answer. Just wait till we publish our numbers in one or two weeks.”

It addition to his role as Chairman, Lopez has also been acting as Team Principal since Eric Boullier departed for McLaren, but he says they will have a permanent replacement in place for next season.

“We are in the process of looking at that. That should be decided sooner rather than later to be fully integrated in 2015,” he said.

When pressed if it would be someone the paddock was familiar with he added: “Yes, there is a chance.”