During recent testing the Woking team struggled to keep pace with the Renaults, leading Kimi Raikkonen to claim that McLaren's Mercedes engine was it's "weakest link."

He said: "On the engine side we have a lot of work to do. (Mercedes) are not where they should be and they need to improve.

"We have been testing for a long time but we have not been able to make progress.

"(The engine) is definitely our weakest link now."

In an attempt to fix the problem, Mercedes have redesigned their FO 108S engine, which according to Autosport, is not only more reliable than the current one, but  also has 60 horsepower more power.

McLaren are expected to test the new unit during this week's Jerez programme