Lewis Hamilton says this year's title battle with team-mate Nico Rosberg is "a lot more intense" than his previous fights in 2007 and 2008.

In his first two years in the sport driving for McLaren, Hamilton entered the final race of the season leading the drivers' championship. However, in 2007 Kimi Raikkonen snatched the title, while Hamilton was just able to hold off Felipe Massa the following year to claim his only F1 world championship to date.

Speaking as part of the Forever Faster campaign by Mercedes team partner PUMA, Hamilton said this season had been notably different to the fights with the Ferrari drivers.

"The battle does feel a lot more intense this year," Hamilton said. "When I was racing against Raikkonen and Massa, they were in a different team and their cars had different strengths and weaknesses to my car and, in my team, it was just me that was really competing with them.

"Now I'm racing against a guy who has the same car as me - we both have access to exactly the same data and feedback so it is really hard to try and be ahead. It's a little bit like playing poker - you have a set of cards and the other guy is not supposed to know what you got, but Nico and I can see each other's cards so then it's more difficult to beat each other."

And Hamilton confirmed that the current fight against his own team-mate was more difficult to approach than against a driver in another team.

"Definitely more challenging, because you have to find ways to create small margins. And so what you do is bring your skills, things that you've learned, things you can put into the mix. And you always have to move forward - you can't just be good and that will be enough, you have to keep pushing the boundaries, because every time you take a step forward the other guy makes an equal step so you have to keep doing it."