McLaren racing director Eric Boullier says he was 100 percent certain Fernando Alonso would leave the team after its disastrous third season of its Honda partnership in Formula 1.

In the new Amazon Original documentary which gives an insider view into McLaren-Honda’s 2017 F1 season, which unfolds as the final straw to its Honda relationship, Boullier holds a meeting with McLaren Chief Operating Officer Jonathan Neale after the opening pre-season test in Spain.

After constant disruption due to an unreliable engine, with Alonso venting his full frustration at the situation after his opening day of running with the MCL32, Boullier is seen to be adamant Alonso will leave the team and expresses his fears of a team collapse.

“He's going to say 'you know what guys? Ciao bello',” Boullier said. “He will not stay. I am 100 percent sure he will not stay.

“After this testing, obviously Fernando is quite pissed off. He is clearly saying 'I may reconsider my position to race because I'm not going to survive another year like this'. My main worry at this time is not to have the team collapsing. I know the domino effect as well.

“In this business you know how it works. When you are weak, people they come, they just poach who they want. It takes years to build an F1 team but you can kill it in six months.”

While Alonso’s future at McLaren remained uncertain for the bulk of the 2017 F1 season the Spaniard re-signed in October on a one-year deal with extension options after the Woking-based team secured Renault power units from 2018.

Alonso is gearing up for F1 pre-season testing at Circuit de Catalunya which begins on February 26 with the team’s launch held on February 23 to unveil its new-look MCL33 car equipped with Renault engines.