Porsche’s 919 Hybrid will race in a low-downforce configuration developed for the Le Mans 24 Hours at this weekend’s World Endurance Championship opener at Silverstone.

The German manufacturer has finally confirmed its intentions after previously refusing to commit to which of the two aerodynamic specifications permitted this season it would take to the British round.

It will also run its pair of updated 919s in Le Mans spec at the Spa WEC race at the start of next month and will not give a debut to the high-downforce version of the car until the Nurburgring event in mid-July.

That means it will be disadvantaged this weekend against sole LMP1 rival Toyota, which will run its TS050 HYBRIDs in high-downforce spec.

Porsche LMP1 team principal Andreas Seidl said that a decision had been made to “focus on developing and testing our Le Mans aerodynamics until the third race of the season is over”.

“This means low downforce for the benefit of low drag, and this unavoidably will be a disadvantage in Silverstone,” he explained.

“After Le Mans in June we will arm the 919 with more downforce for the remaining championship rounds.”

Reigning WEC champion Neel Jani said that Porsche would be “aerodynamically compromised” at a circuit that demands high levels of downforce for its multiple fast corners.

A revised rule for 2017 has reduced the number of aerodynamic configurations allowed to each LMP1 manufacturer from three to two per season.

No major changes are permitted once a specification of bodywork has been homologated ahead of its first race.

Porsche’s decision will allow it to continue to develop its high-downforce car prior to the second, post-Le Mans leg of the WEC.

Toyota plans to run its pair of full-season WEC entries in high-downforce configuration at Spa and its additional third entry in Le Mans spec.