Series boss Frederic Lequien categorically stated that the field would be increased to 40 in the wake of the publication of next year's entry list of 37 cars.
"We will go to 40 cars in 2025, definitely," said Lequein. "I can tell you it is a kind of obsession at the office, but it is really difficult to find the right balance.
"We will not have the capacity to take everyone, because we could have 43, 44, 45 cars in 2025."
Lequien stressed that an increase to more than 40 cars would not be possible.
"When you participate in the WEC you automatically qualify for the Le Mans 24 Hours and at Le Mans we have only 62 places - we have to pay attention to that," he explained.
More than 40 entries in the WEC would reduce the number of cars race organiser the ACO and the FIA could invite from its associated series, the European and Asian Le Mans Series and the IMSA SportsCar Championship in North America.
This year at Le Mans there were 10 automatic entries from the European and Asian series, as well as three nominated by the IMSA organisation.
The ACO has guaranteed 15 grid spots for LMP2 machinery in 2024 following the disappearance of the class from the full WEC championship.
The plan to go to 40 cars was first outlined to Autosport by Pierre Fillon, president of WEC co-organiser the Automobile Club de l'Ouest, in September.
It was subsequently admitted earlier this month that the expansion had been shelved and that the grid would stay at 37 cars, though the desire to increase the field remained current.
The 2023 limit has been set by the capacity of the pit complexes at the Imola and Austin tracks that host WEC rounds in April and September respectively.
The WEC will need to increase the grid in 2025 when Aston Martin and the Heart of Racing team is due to arrive with at least one Valkyrie Le Mans Hypercar and the Iron Lynx factory Lamborghini squad is aiming to expand from one to two SC63 LMDhs in the Hypercar division.
A maximum capacity of 40 cars would mean there would only be room for one further car assuming that no competitors drop out of the championship and the LMGT3 field remains at nine manufacturers and 18 cars.
Lequien explained that how the WEC will accommodate the extra cars at tracks where there are fewer than 40 pitboxes remains a work in progress.
"We are currently discussing with everyone, all the teams, to check all the possibilities, especially in LMGT3 to share the garages [with each team running two cars from one box]," he said.
"There are so many parameters that need to be taken into consideration."
Lequien also didn't rule out additional cars joining the WEC in 2024 where the number of pits allowed.
