The process of defining the shape of the 2020-21 FIA World Endurance Championship top-level prototype regulations is “still not fully finished” according to Toyota Gazoo Racing director Rob Leupen.

A key meeting was held on May 16 amid encroaching deadlines for an absolute definition of the formula that will replace LMP1 after next season.

Leupen said ahead of the Le Mans Test Day that Toyota could “make some steps” towards deciding on its involvement in the class, but there are still some elements to clarify.

An announcement is expected from the ACO during its annual press conference on June 14.

“[The meeting] was for us to say, OK, now we do with this information,” said Leupen.

“But still, there has to be a final stamp on it. This is what we will know on June 14, maybe a bit before. We will then follow up with our press conference a few hours later, and then we can make our stance.

“At least now we can make some steps, but we now need to get the final one. From our point of view, it’s a situation where we got some clear views on what we could do. But still it’s not fully finished.”

Toyota has long supported the original idea of a top-level class that uses prototype race cars with hypercar styling cues, but the rules were expanded in December to allow production-based hypercars alongside pure race-bred machines.

However, this additional regulation has not been met with universal acceptance by prospective manufacturers.

Leupen, who last month labelled the stalling of the definition process as “ridiculous”, reiterated that the tight schedule to be on-track for 2020 is putting Toyota under pressure resource-wise.

It comes despite Toyota believed to have already begun on initial development work for a car based on the draft regulations released in December.

“As the time is getting shorter and shorter, you have to, otherwise you are losing time and you won’t be able to put it on the road in time,” he said.

“You have to test the new car in a 30-hour endurance test. You will not put the car on the ground [and be instantly durable] as we did in 2012. We know what’s going to happen.

“We were here in Le Mans: yes, we were quick, but the durability was not good and we left the race after 12 hours.

“You need the time and we want to do it in an economical way. It should be a regulation which is longer term.

“It means you should not have to redo a car after half a year because this is then not budget efficient at all. We have no issue with risk, but you would like to have a calculated risk.

“We have a lot of other programs running in Cologne and you cannot jeopardize those. This is something that we need to take care of.”

Sportscar365 understands that the latest proposal calls for the retention of prototype-based hypercars but with less power and more aero, along with a smaller front-wheel driven hybrid system, which may no longer be mandatory.

This provision is believed to potentially be in place for the Red Bull-backed project from Aston Martin, which has been pursuing a program with a prototype based on the AMR Valkyrie.

“We are still thinking [about] what we got on May 16: OK. But now we would like to see as soon as possible the final step,” Leupen said.

“The technical people are still in the final defining stage. When this is out, then it can all go very quick. The details are still to be put to paper.”

John Dagys contributed to this report