David Coulthard has suggested that the fascinating internecine scrap due to play out at McLaren-Mercedes this year between the last two F1 World Champions and countrymen Lewis Hamilton and Jenson Button is impossible to predict - with high stakes indeed for both the winner and the loser.

Whichever way you look at it, Button and Hamilton are likely to end the forthcoming campaign with one of their reputations having been enhanced and the other having seen his stock take a nosedive - and the general consensus is that it is the 2008 world champion who will be left smiling and his title-winning successor licking his wounds. Or, as Michael Schumacher's erstwhile Ferrari team-mate Eddie Irvine so eloquently phrased it, Button will be 'murdered' by Hamilton [see separate story - click here].

The outspoken Irishman's former sparring partner and rival Coulthard, however, contends that the duel will be nowhere near as clear-cut. Having competed against both Hamilton and Button on the track before hanging up his own helmet following 15 seasons at the highest level and turning his talents to punditry for the BBC's F1 coverage, the Scot warns against jumping to any conclusions too soon.

"I think that's true," the 13-time grand prix-winner told Crash.net Radio, when asked whether he - like many others - believes that Button has entered the lion's den in joining a team that most hold to be all-but built around his new team-mate and existing incumbent Hamilton. "He could have stayed within the comfort of Brawn - which has obviously now become Mercedes Grand Prix - and defended his title there, but what he's done is to give us all the opportunity to really see how good he is.

"I know them both personally and this is going to sound a bit sycophantic, but I think they're both well-rounded individuals and great drivers, and I'm curious, genuinely curious, to know which one is going to best handle the 2010 regulations and the challenge of competing against each other.

"There's no question that Lewis Hamilton is a great driver and there's no question that Jenson is a great driver, but one of those guys come the end of the season will be on top - and it's going to be fascinating to watch. I don't know the answer - let's wait and see."

One other major unknown as the curtain-raising Bahrain Grand Prix at Sakhir races into view in less than three weeks' time now is just how much of a threat to the sharp end of proceedings returning F1 legend Schumacher will turn out to be, and whether three years away from the cockpit and the cut-and-thrust of competitive action will have dimmed the German's scintillating raw pace and thirst for the fight.

"Again, who knows?" Coulthard mused. "This is just a fantastic opportunity for us to see if Michael can have a second career and compete against these young guys in their twenties at 41-years-old. Let's follow the year as it develops..."