After the most troubled of pre-seasons, McLaren and engine suppliers Honda head into 2017’s season-opening Australian GP facing mounting questions over the long-term future of their partnership.

Sky Sports F1's Ted Kravitz analyses whether hitting the 'nuclear' button is really an option for McLaren, what they will want underperforming Honda to change, and the chances of former partners Mercedes ever offering an alternative way out.

Could McLaren really split with Honda?

Ted Kravitz: "Well, let's consider the origins first: This story originated in the Spanish press on the penultimate day of the first winter test, so you can speculate whether it originated from the Fernando Alonso camp or not, but although unsubstantiated, it rang true at the time.

"I asked Eric Boullier about it on the Notebook that evening (watch below) and rather than a flat out denial, he just said he 'wasn't going to go into this debate'.

Ted Kravitz rounds up the penultimate day of Test One at Barcelona and speaks to McLaren chief Eric Boullier Ted Kravitz rounds up the penultimate day of Test One at Barcelona and speaks to McLaren chief Eric Boullier

"But what we do believe is that as soon as McLaren saw evidence there was not going to be the immediate leap forward in performance that Honda had promised for 2017 they had to start considering all options, which includes shopping around for a future alternative engine supply.

McLaren considering engine options

"The thing we keep hearing from McLaren is "we are changing in order to win again" and "we must win again and we will win again". So if you keep that in mind as the overriding ambition of the team, then even what would be seen as the nuclear option, which is divorcing from Honda, doesn't seem as unthinkable as it once might have been.

"You should also bear in mind that the decision to reunite Honda was made by Ron Dennis and Martin Whitmarsh back in 2013, so new executive director Zak Brown and the McLaren executive committee (or ExCom, as the team themselves snappily call it) could drop Honda while still reasonably arguing that it wasn't their idea in the first place.

"Honda have said today that they are in Formula 1 for the long-term, which is true, as they could still go off and supply another team. No problem there. Williams or Sauber could pick them up, while McLaren could go back to Mercedes, do a deal with Renault or, whisper it, perhaps even Ferrari.

"It would be ruthless on Brown's part, but that's Formula 1."

Could McLaren switch engines as early as this season?

TK: "Technically it is possible, but you'd need around six months from the point we are at now to get a car that would actually be better in performance.

"After all, you would have to redesign to large parts of it to fit a different power unit and the various internals. If you did it too quickly it's debatable whether the complete package would actually be faster than what they've got at the moment.

Alonso: Honda are to blame

"So it is possible, but it's more probable that they'd start next year's project around a different engine if that's the route McLaren opt to go down.

"But let's bear one other thing in mind: they would have to do without Honda's money were they to initiate a split. A large part of McLaren's racing budget currently comes from Honda, so I doubt whether they can financially afford to split as things stand.

"So we should probably view all of this as giving Honda a kick up the backside."

Fernando Alonso says Honda's new F1 engine isn't providing enough power Fernando Alonso says Honda's new F1 engine isn't providing enough power

Would Mercedes really be interested in supplying McLaren again anyway?

TK: "Good question: why would Mercedes want to supply one of F1's other grandee teams, albeit one which is something of a sleeping giant at the moment, with their class-leading power units?

"Well, since Manor went bust in January, Mercedes have certainly got the capacity to supply a third customer team and, funnily enough, it would be almost a professional challenge to have McLaren on their roster again.

'McLaren would win with Mercedes power'

"Mercedes chief Toto Wolff would see it as a challenge to supply McLaren and would hope to beat them in the chassis department. If they did that then it would be professionally very satisfying for everyone at Brackley.

"Then there's the debate about whether you'd believe a Mercedes customer would ever be able to beat the works team because they're not as entrenched in each other's ways of working, which leads us back to the very beginning and why Ron Dennis wanted to split with Mercedes in the first place.

"He was very definitely of the view it is not possible for a customer team to beat the factory team. And if he's right then Wolff would have no fear of being upstaged however good the McLaren chassis is."

So where do McLaren and Honda go now? What do McLaren want their engine suppliers to change?

TK: "I keep thinking about something Boullier, McLaren's racing director, told me at testing when I asked him about the design fault with the MCL32's oil tank which curtailed the new car's running on the first day.

"I suggested this kind of problem would normally be fixed in a computer simulation programme before the car even hits the track and he said 'yes, but if you change some processes maybe you can miss some of this'.

"I still wonder what he's referring to. Has Honda changed the way it works which might have allowed these problems to creep into their power unit?

"McLaren will be demanding new ideas and the money to go with it to make a quick change to the power unit. They can't do anything about the first four races now - McLaren are effectively going to write those off in all likelihood - but this is putting pressure on Honda to commit the man hours and the money to getting it sorted for mid to late May when the European season begins."

Watch the 2017 F1 season on Sky Sports F1 - and in Ultra HD for the first time! Get Sky F1 for the new season!