Jenson Button has said Lewis Hamilton can be 'unbeatable' if the Mercedes driver is in the right frame of mind throughout the season.

The British driver sealed his fifth win this year with the 2014 British Grand Prix earlier this month. In the same race, Hamilton's Mercedes teammate Nico Rosberg failed to finish the race due to a problem with the gear box. This put the 29-year-old driver in second place and just four points behind championship leader Rosberg.

Hamilton was Button's old teammate at McLaren. Button believes Rosberg can have the edge over his compatriot, but has backed the British driver to win his second career championship – provided Hamilton's head is in right place.

"People say Lewis Hamilton is quicker but Nico Rosberg is more intelligent, I don't know though," Button told talkSPORT.

"I know how quick Lewis is and if his head is in the right place he will be unbeatable [in the title race]."

McLaren are having a poor run in this year's F1 as they sit sixth in the constructor's table with 90 points, 236 points behind the table toppers Mercedes. However, Button remains confident that he and Kevin Magnussen will help McLaren win races in "just a matter of time".

"It's been a very tough year. We're not at the front, where we're used to being, but we're getting stronger. The British Grand Prix showed that as we qualified third in tricky conditions and almost got a podium," the McLaren driver said.

"We've got the best engine, which is the Mercedes, so we don't have that excuse. We just haven't built a good enough car to win races this year. We're working hard though and there have been a lot of improvements already. We will win races, it's just a matter of time."

"It is frustrating because when you have won races and a championship before, nothing else is good enough, but we're on the right track and that's the most important thing," Button concluded.