Formula One could be poised for its first technical row of the year as questions have been raised as to the legality of Lotus' new design.

On Friday, the Enstone-based marque revealed a computer mock-up of the E22 that incorporated an unusual twin-pronged nose.

The noses of this year's cars have become a major talking point given the change to the regulations, with many deriding them as 'ugly'.

The problem centres around the fact there is a discrepancy between the rules regarding the chassis height and that relating to the nose.

In order to ensure the car is aerodynamically efficient, the shape of the noses have been altered significantly, and not for the better.

Toro Rosso team principal Franz Tost, after the unveiling of the STR9 in the pitlane at Jerez - scene of this week's first test that begins on Tuesday - claimed the new nose concept has no place in F1.

The Toro Rosso design caused a stir on social media given its highly-distinctive, protruding shape.

But it is the 'twin-tusk' nose that has raised eyebrows, leaving Toro Rosso technical director James Key to ponder its legitimacy.

"The Lotus nose needs clarification, but it's a very clever idea," said Key.

"We looked at it early on, when the car was quite a bit less mature than now, and in theory it was working well.

"But in reality we felt it had too many drawbacks so we didn't pursue that, but we kind of understand where they've gone with it.

"It could be worth a revisit at some point when things have calmed down a bit.

"The question really is, is it within the spirit (of the regulations)? We'll see.

"It's really down to the FIA and Lotus to discuss that, obviously. If they run it, then it's passed the impact test, and they're happy.

"I don't think it's illegal, it's just whether it's in the spirit of the regs.

"Our interpretation of a similar idea was with a slightly different front of the nose, to the point where we were happy that it would be accepted within the spirit of the regs.

"I'm not saying the Lotus one isn't, but it's probably the most extreme out there."

Lotus are the only one of the 11 teams not in Jerez this week as they instead will fully reveal their car at the second test in Bahrain next month.

Marussia, however, will not run on Tuesday due to a late technical issue with the MR03, which is to be addressed at the team's factory in Banbury rather than in Spain.

It means Marussia could be hard pressed to get on the circuit on Wednesday, and may have to limit themselves to the final two days on Thursday and Friday.

Mercedes, meanwhile, unveil their car in Jerez on Tuesday adorned with a special message for Michael Schumacher.

The seven-times champion remains in an induced coma at the University of Grenoble hospital after suffering brain injuries in a skiing accident at the French Alpine resort of Meribel at the end of last month.

Concerns are growing as to whether Schumacher will make a recovery - should he ever awake again - given the length of time the 45-year-old has remained in his current condition.

In playing their part, and given Schumacher spent three years with Mercedes from 2010-2012, the car will carry the words '#KeepFightingMichael'.