The admission comes against a backdrop of speculation that the German manufacturer is gearing up to end its involvement in P1 at the end of this season.

Porsche LMP1 team principal Andreas Seidl said: "We will make the decision before the end of July."

He refused to elaborate on the comment, saying he was focusing on this weekend's fourth round of the WEC at the Nurburgring.

Porsche is, in theory, committed to racing on in LMP1 until the end of the 2018 season, after extending its initial three-year race programme covering 2014-'16 in August 2015.

Speculation about a pull-out has been fuelled by the presence of senior Porsche figures at the Formula E races at Monaco and Berlin.

Porsche extended its record tally of overall victories in the Le Mans 24 Hours last month to 19 – scoring a third consecutive win in the French endurance classic.

Toyota's view

LMP1 rivals Toyota said that it was unclear what the withdrawal of Porsche would mean for its plans, which include a firm commitment to the WEC until the end of 2019.

"At the moment, with the situation we know, our management has committed to next year," said Toyota Motorsport GmbH technical director Pascal Vasselon.

The disappearance of Porsche in the wake of Audi's withdrawal at the end of 2016 "would be a problem" he admitted.

"We will rethink our strategy when the conditions change: I cannot elaborate more on something that has not materialised," he said. "What our position would be, I do not know, but sure, we need competitors."

Vasselon said that he was hopeful that new manufacturers would enter the P1 arena when new regulations for 2020, which were announced during the week of the Le Mans 24 Hours last month, come into force.