Kamui Kobayashi has dismissed criticism the latest generation of Formula One car is ugly.

Sauber drivers Kobayashi and Sergio Perez unveiled their latest car, the C31, on a bright, sunny morning at the Circuito de Jerez in southern Spain.

Like the Ferrari, Caterham, Force India and Lotus before it, the car has the now familiar-looking stepped 'platypus-style' nose to meet the latest FIA regulations regarding the height of the front wing.

Only McLaren has taken a different route to date, with the nose on the MP4-27 a smoother design, and now only time will tell if they have taken a wrong turn or are a step ahead of their rivals.

Asked about the 'ugly' design of the car Japanese star Kobayashi, who finished 12th in last year's championship with 30 points, said: "You think it's ugly?

"If everybody has the same style of car then it's not ugly. Only the McLaren is different, so we will see.

"Yes, it looks in the beginning a bit ugly, but a couple of years ago we went with a high wing and everybody said that car was ugly.

"Now everybody is used to it, so in a couple of months I'm sure we won't have these comments any more."

Mexican Perez, four places and 16 points behind Kobayashi, added: "Our team has done a very good job over the winter and towards the end of last year developing our car.

"I'm confident we have a strong car, a strong package, with our target to definitely improve on last year."

Perez, meanwhile, believes the Swiss team will overcome the shock departure of technical director James Key on Friday.

Key had naturally played a significant role in developing the car, so his exit three days ago came out of the blue.

Perez said: "The way I see it we have a really strong team.

"James was a key person, but the team will be together and remain very strong."

Explaining Key's departure, CEO Monisha Kaltenborn said: "For a while both sides felt things were not working out, and not what was expected. What has happened is a result of that.

"James joined us during a handover period from a factory team to a private team.

"His contribution was very valuable, but we now have a structure, long term, that is the right one going forward.

"The people now in charge of the performance of the car have been there for some time, so we don't expect any kind of destabilisation.

"We think we are well prepared, we have stability and continuity, especially with our drivers.

"We have expanded our factory in Hinwil, we now have around 300 employees, so that sets us up well for the future."

With regard to the team's targets for the season, after finishing seventh in the constructors' championship last season, team boss Peter Sauber said: "It's the same as every year - we want to score points on a regular basis.

"We also want to improve in the championship significantly, and it is important for us to finish in the top 10 in qualifying on a regular basis."

Kaltenborn, meanwhile, has confirmed Sauber are now no longer a member of the Formula One Teams' Association.

It means at this stage seven teams remain, with Sauber, Red Bull, Ferrari, Toro Rosso and Hispania all having withdrawn, seemingly weakening further FOTA's unity.