Jenson Button has moved to defend former team-mate Lewis Hamilton, insisting that the Mercedes driver has not lost any of his raw speed.
Hamilton, who made the switch from McLaren to Mercedes for the 2013 season, has often been outpaced by new team-mate Nico Rosberg this campaign, and has failed to win a race.
However, Hamilton still holds the better position of the two in the drivers' championship with 77 points, while Rosberg has scored 57.
But Jenson Button, who himself has struggled with performance from his McLaren, does not believe Hamilton has lost any of his speed: "For Lewis, it is the same as it is for all of us - if he does not have a car balance that suits him, then it is not easy,” he told German Magazine Auto Motor und Sport.
"And, of course, Nico is fast. But Lewis has not lost his speed. It is still there. He will come back and then he will shock you all.”
Hamilton has bettered Rosberg's result in five of the seven grand prix's so far this season, and Button still believes Hamilton has the speed: “You have to be fair. He has at least scored significantly more points than Nico. Lewis is incredibly fast." He added.
Button also gave his views on the upcoming FIA international tribunal on Thursday, in which Mercedes must attend for their role in a 1,000km Pirelli tyre test after the Spanish Grand Prix.
The 33-year-old says he believes Mercedes gained no advantage from the test, and that he trusts both Hamilton and Nico Rosberg: “Both drivers said no,” he added.
“You have to believe them. Otherwise they would be liars. So I believe them."