It's a 'no-brainer' to continue Mercedes-Hamilton partnership, says Wolff

Mercedes boss Toto Wolff has responded to speculation that Lewis Hamilton has yet to sign his news contract with the constructor, insisting that the agreement is 'a matter of time' and it is a 'no-brainer' for the world champion to continue with them next season.

Rumours have once again surfaced that Hamilton is stalling on a new agreement to keep him with Mercedes beyond the end of the 2018 season, when his current contract expires.

Hamilton, who has won three world titles with the German giants, would have no shortage of big-money offers but Wolff insists that he isn't concerned, because a long-term arrangement with the 33-year-old is inevitable.

He said: ""Lewis has become such an important pillar within the team.

"It is a no-brainer that we continue with each other. The discussions are ongoing and with a very positive mind-set. It is just a matter of time, when we seal it and put the signature to the document."

Wolff also addressed the improved challenge from rivals Ferrari in 2018 who, with Sebastian Vettel, were a real threat to Mercedes' dominance until reliability issues in the second half of the season put paid to their efforts.

He added that the team are in a positive frame of mind to build on what they achieved in 2017 and ensure they remain number one.

"The mood is good, it's especially good because today we will be firing up the car for the first time. What has been designed is coming together, and is coming alive.

"It never goes seamlessly or smoothly because you're trying to push the boundaries, making the car as light as possible and as quick as possible. We've had a good winter, I would say, no real drama – but there is always stress at this time of year."