Sky F1's Simon Lazenby and Martin Brundle discuss the big talking points ahead of the opening F1 race of 2018, the Australian GP

Formula 1 faces the most important six months in its history at the start of 2018, according to Sky Sports' Martin Brundle.

The sport reconvenes after its winter break at this weekend's Australian GP amid mounting hopes that the new season could produce an exciting three-team title battle.

But the backdrop to the season's start also includes considerable uncertainty around the topic set to dominate the year's off-track agenda - the 2021 regulations - following Ferrari's threat to leave the sport.

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Before heading to Melbourne, Sky Sports F1 expert analyst Brundle tweeted his hopes for the season and concluded: "The most important six months in F1 history coming up."

So what makes the opening half of F1 2018 so pivotal to the sport's long-term future?

"I fully believe that statement," said Brundle, whose career in F1, as first a driver and now commentator, is entering its 35th year.

"The media, sporting and motoring landscape is changing both dramatically and dramatically quickly and so Formula 1 2021 has to be absolutely right first time.

"That's a huge challenge. Where are we heading and what do we do? What do we stand for? How do we engage the fans and sponsors? What are we trying to achieve?

"If you're going to get 2021 right, the rules need to be in place now. If you want to attract Aston Martin and others into the business, and you want to keep teams and manufacturers in the business, it's a hell of a challenge.

"[F1 managing director] Ross Brawn is a very good man for this. He's a bit of unicorn in some respects because he can do technical, sporting, political and financial - he's proven that over the decades and that's a very unique skillset. Has he got total support? Is he fully empowered?

"Somebody is going to have to be supremely confident, brave, empowered and competent in going 'here's the template of where we think Formula 1 could be in 2021 and for the next decade - either you're in or you're out'.

"Hence that's got to be done well within the next six months because if you're going to join F1 in 2021 you need to be starting your engine now to be ready and competitive.

"September is probably too late. I might even be wrong on six months, it might even be three months in all reality."

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The challenge ahead for F1
2021 is considered a critical juncture for the sport owing to the fact that it will be the first year of the next engine formula and the first season after the present commercial deals with the teams expire.

Ferrari have been vocal in their opposition to the proposed engine changes, with company president Sergio Marchionne insisting they would consider quitting F1 if they do not agree with the plans introduced.

Mercedes' Toto Wolff, who has said the world champions' share a similar viewpoint, this week warned "don't mess with Sergio Marchionne".

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Brundle can see both sides of the argument, but believes F1 must evolve to increase its sustainability.

"The massively significant subplot to all this is Ferrari and any kind of breakaway," he said.

"There are a lot of different needs in the sport and the model we have at the moment is unsustainable moving forward.

"Mercedes have done an incredible job. I don't blame them at all for anything we've currently got because they've just done an outstanding job. Formula 1 is about excellence at the end of the day, it's not lowest common denominator.

"If we walked a mile in the shoes of Sergio Marchionne at Ferrari and the powerbrokers at Mercedes-Benz, why would they want to change anything? They're in a totally dominant position, financially enhanced, they're winning and they're the likeliest to win again this year. It's like the turkey voting for Christmas.

"On the one hand, you've got the big players saying 'no, no, no - this is what we want to do', while on the other you've got the rest of the grid going 'we can't survive like this'."

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Hamilton and Vettel ready to do battle

But while political wrangling may return more prominently to the surface in 2018, Brundle says there are plenty of reasons for excitement too.

He said: "I consider myself a Formula 1 fan, I think I've earned that right. I stood on the banks of Silverstone and Brands Hatch in the 1960s. I've been to over 500 of these races. I wouldn't presume to speak on behalf of the fans, they can speak for themselves, but I do consider myself a fan. I've been involved in most aspects of Formula 1 in the last 35 years.

"I wouldn't want to talk anything down because I love Formula 1 and I couldn't be more excited for year 35 as when I walked in the paddock here in Melbourne. Formula 1 still very much excites me, but the product has to change moving forward because of all the parameters I talked about."

And his big on-track wishes for 2018?

"The midfield is going to be great," he added. "McLaren, Renault, Haas, Force India and Williams - it could be brutal.

"We've just got everything crossed that Ferrari and Red Bull can keep Mercedes in view."

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