Button must be No 1 - Stewart
Sir Jackie Stewart has urged Jenson Button to consider himself McLaren's number one driver this season.
McLaren team principal Martin Whitmarsh this week insisted Sergio Perez will have equal billing with Button following the Mexican's arrival as replacement for Lewis Hamilton.
It has always been McLaren's policy that no driver is given preferential treatment over the other, regardless of age or experience.
But with three seasons with McLaren behind him, and ahead of his 14th year in Formula One, Stewart feels Button now has the opportunity to impose himself on the team and push for his second world title.
Speaking to Press Association Sport, three-time world champion Stewart said: "It's not a question of equal footing this year.
"You've someone in Jenson who knows the engineers, telemetry people, knows the business, and who has been there, seen it and done it.
"So I think he can do it again (win the world title) with the right equipment, and there cannot be a better supplier of that equipment than McLaren.
"They are about as good as they come. They've got the facilities, so many assets, so yes, he can do it if the car is good enough and he is psyched up enough.
"He no longer has to keep up with Lewis and that's a mental thing, so he has to see himself as the number one driver, and that McLaren are depending on him."
For Stewart, the only question mark surrounding Button is whether he can win races on a consistent basis.
Button has won eight races with McLaren, including the final one of last season in Brazil, but never enjoyed back-to-back triumphs.
"When he wins races they are beautifully-controlled races," Stewart added. "You just know he is not going to fly off the race track or make huge errors of judgment. He is very solid.
"Whether he has what it takes to be a serial winner (with McLaren), the jury is still out because he hasn't done that yet."
With stability in the regulations from last season through to the forthcoming campaign that starts on March 17 in Australia, Stewart fears Red Bull and Sebastian Vettel will make it four titles in a row.
Asked whether they would dominate again, Stewart said: "There's a big risk of that happening.
"That's simply because (designer) Adrian Newey has an amazing energy level and deep wells of adrenalin in him somewhere.
"If he continues to have the same enthusiasm and interest, and with him being so creative, then it's tough for anybody to keep up."