Lewis Hamilton has identified what he considers his "greatest" desire looking forward in his career, as speculation over his future continues.

The current world champion is out of contract at Mercedes at the end of this season and despite persistent reassurances that an extension is a formality, still it remains unsigned.

As a result, it leads to the obvious speculation as to whether Hamilton is considering retiring from Formula 1 like his teammate Nico Rosberg in 2016.

However, speaking ahead of this weekend's French GP, he once again claimed his motivation for both the sport and for further success remains undimmed.

“There are a lot of different things that motivate me. My desire to win this championship is greater than it’s ever been,” Hamilton was quoted by PlanetF1.

“I do all of these different things in my life and I have all of these other interests, but none of this would be possible without racing.

“At the core of me is racing, above everything else.

“So much time, dedication and sacrifice has gone into getting where I am today and I love what I do; I love the competition and the challenge.”

Many will hope the fire inside the belly is a little stronger heading to the French Grand Prix this weekend after losing the championship lead to Sebastian Vettel following a disappointing fifth-place finish last time out in Canada.

Interestingly, France's return means the record Hamilton did hold of winning every race on the calendar at least once is now untrue, having failed to win his two previous races in the country held at Magny-Cours in 2007 and 2008.

Previously, the 33-year-old has also admitted some disappointment about the race changing venues, with Circuit Paul Ricard now hosting, and after three uninspiring races, he is unsure how Le Castellet will fair.

“I really don’t know what it’s going to provide,” he admitted.

“Is it going to be a boring race like [Montreal] or an exciting one? Is it going to be one like Baku? I really couldn’t tell you, absolutely no idea.

“I hope for France it’s a great one, I really do. I’ve not watched these races so I don’t know what you guys feel.”