Such is the discontent between McLaren and Honda that Eric Boullier openly admitted that the Woking team would be race winners, if only they were using a different power unit.
Struggling for reliability and pace throughout this year's pre-season testing, McLaren have pointed the finger at engine partner Honda.
Speaking at the start of the second test, double World Champion Fernando Alonso said: "We have only one problem which is the power unit.
"There is no reliability and there is no power. We are 30kph down on the straight."
Honda being the problem is a sentiment echoed, and publicly by Racing Director Boullier.
In a recent interview with Spanish daily AS, he was asked if McLaren could win races if they had remained with Mercedes.
He replied: "I think we would."
Pressed on whether wins with Mercedes power would be possible in 2017, he said: "Yes, we'd be winning again."
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