Alonso needs to believe in us as we believe in him - Boullier

McLaren racing director Eric Boullier wants nothing more than to see Fernando Alonso extend his stay at Woking, but he also insists that faith is a two-way street.

McLaren's future with engine partner Honda is uncertain to say the least, with a decision on the partnership's fate for 2018 looming large.

Fernando Alonso says that he will decide his own future plans in September with a lot depending on McLaren's level of performance by then and its plans for 2018.

While Boullier insists that McLaren will do its best to convince the Spaniard it can deliver the goods next season, regardless of the identity of its engine partner, the Frenchman also underlines the necessity for reciprocity when it comes to commitment.

"I prefer that he (Alonso) stay with us, but under the condition that he believes in our project," Boullier said in an interview with Nextgen-Auto.com.

"A driver who does not believe in us is not very useful."

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Asked whether he thought the two-time world champion still had faith in McLaren, Boullier was evasive.

"You'll have to ask him it's not up to me to answer for him," he quipped.

Alonso's options for next season appear very limited outside of McLaren, with both Ferrari and Mercedes publicly stating that they are not interested in the driver's services, an attitude which Boullier labels as predictable.

"I'm not surprised. Every world champion wants to measure himself against the best but not necessarily with the same equipment, so the goal is to beat the others," said Boullier.

"But letting the wolf among the sheep is never a good idea. When you enjoy number one status, like Vettel and Hamilton, even if they won't say it officially, they are the leader in their respective team.

"They don't want someone who will screw up their plans."

But Alonso's rejection by Mercedes and Ferrari isn't perceived by Boullier as necessarily positive for McLaren and its efforts to keep its driver.

"It's more complicated than that as it isn't always the driver who decides," he adds.

"At the end of the day, everyone does what they want. I'm interested in having two drivers who believe in the 'McLaren-Honda project'.

"With Fernando, whatever happens, he'll go wherever he wants to go, whether it means leaving or staying with us. We'll see...