Raikkonen spoke in public for the first time in Singapore on Thursday about his decision not to renew his Lotus contract and instead opt for a return to Ferrari in 2014 and was frank about the reasons why, announcing: "I haven't got my salary."

Reports that Lotus were behind in their payments to the 2007 World Champion had swirled for some time and Raikkonen's revelation was not widely regarded as being a particular surprise.

But speaking to Sky Sports F1 on Friday, Lotus's Team Principal admitted he was unsure why Raikkonen had decided to disclose the matter.

Put to him by Martin Brundle that the sight of one of the sport's top drivers having to admit he was not being paid reflected badly on F1, Boullier replied: "It's obviously a bad message, but I don't know why he decided to publicly speak about his finance situation."

Although a deal to sell 35% of the Lotus team to a consortium of investors under the banner of Infinity Racing was announced as long ago as June, the money from the agreement is not believed to have yet come through to the Enstone outfit.

Boullier says Lotus have made no secret of the difficulties they have faced to make ends meet as a private team in the current financial market and admitted they also delayed some payments to Raikkonen last year, although these were ultimately paid to the Finn in full.

"It's maybe the opportunity to just wake up and understand when all the teams are talking about cutting costs. [In] the car manufacturer era last decade everything was too much, but today Formula 1's business style and the revenue stream we can generate as a private team is quite difficult and you have to rely on your shareholders today," he explained.

"We have not hid anything, we are trying to bring some new investors on board which would allow us to secure some new sponsorship and this is where we are nearly, nearly done.

"Unfortunately the timing is not the same for the people outside the paddock than the one we have here. It's true that we have concentrated this year on paying our people, on trying to pay suppliers and make sure we can keep the development rate.

"It's true that we postponed some payment for Kimi. To be honest with you last year was the same, but at the end of the year everything was done and completed.

"So it's not a good message, it's true, but this is the reality and I think people need to face the reality. "

Although admitting Raikkonen's decision to leave at the end of the season was a "disappointment", he made clear the team would strive to show via their on-track results in 2014 that the Finn has made the wrong decision.

"Two years ago nobody would gamble on Kimi and we did it. Obviously we would have loved to carry on this story because the last two years was a nice story between Lotus F1 Team and Kimi Raikkonen," the Frenchman added.

"We would have loved to carry on but this is life and so now we have to bounce back and actually make sure he's going to regret to have left us."