Lewis Hamilton's decision to cash in his chips at McLaren and head for Mercedes in 2013 has more than an element of risk to it, according to three-time F1 world champion Sir Jackie Stewart.

Speaking to Britain's Metro newspaper recently, the 99-race veteran and former team owner said that he could understand Hamilton's reasons for wanting to cut the ties that bound him to the team that nurtured him through the ranks and took him to a world title in only his second F1 season, but insisted that, even without taking Mercedes' mercurial form into account, McLaren would offer a more stable home.

"It's a risk," the Scot claimed, "McLaren are in the business of F1, [while] major carmakers come and go. There's a risk [that], if the Silver Arrows are not successful, it's just a five-minute board decision [to cancel the programme]."

Protracted wrangling over a contract extension at McLaren hinted at discontent between team and driver, with issues such as keeping his trophies among Hamilton's gripes with his current deal, and Stewart admits he can see why the Briton may have wanted a change of scenery.

"Maybe it's a risk worth taking, and I do understand Lewis' psyche," he conceded, "There's an element of him wanting to grow up, he's no longer a little boy in karting. In some areas, he felt that's how he was treated [at McLaren]. It's an emotional decision - but it may not prove to be the right one."

Despite Stewart's doubts, and Mercedes' 2012 season spiralling into disappointment after Nico Rosberg's win in China, another British world champion sees no reason why Hamilton cannot be a success at Brackley.

"When I went to another team [after Williams], I was seen as a leader, so maybe it's easier to take on that role once they're looking to you to give them some direction," he told Britain's Autosport magazine, "Lewis might learn that, he might find that in himself. We don't know but, put in that situation, he might find it."

Hill also included Hamilton, who succeeded him as Britain's 'last' world champion when he triumphed in 2008, among the potential winners this season, along with the most recent British champion, former McLaren team-mate Jenson Button.

"In the old days, there was only ever one team worth driving for, so you had the two best guys in the same team fighting over attention," he noted, "Now you have more than one team [capable of winning] - Jenson Button's got McLaren, Lewis has got Mercedes, Fernando's got Ferrari, Sebastian Vettel's got Red Bull, and Kimi Raikkonen's got Lotus. The reality of the situation is that any of them could win."

Hamilton joins Rosberg in the 2013 Mercedes line-up following the retirement of seven-time world champion Michael Schumacher. The German veteran spared the team's blushes when he scored on his final appearance at Interlagos, preventing it from going pointless through the final six races of 2012. Hamilton has already been to Mercedes' Brackley base to meet his new engineering team and get acquainted with the squad's simulator, but won't be allowed to climb aboard one of its cars until testing starts in February.