The FIA is pushing through a plan to add an extra 2020 Pirelli Formula 1 tyre test to this year's schedule - despite not having unanimous support from teams.
Pirelli's last official test for next year's tyres was run at Paul Ricard last week, with Esteban Ocon at the wheel of a Mercedes W10.
But due to the late finalisation of the target letter that outlines what is required of it for 2020 in terms of tyre behaviour, Pirelli has requested an extra test to allow it to do more running with a new construction.
The test is provisionally scheduled for October 7-8 at Barcelona.
The testing schedule is enshrined in the FIA Sporting Regulations so, in theory, any change after April 30 requires the unanimous support of the teams.
After a discussion at last week's meeting in Geneva, where FIA president Jean Todt backed the move to allow the test and therefore a construction change, two teams opposed its addition when it came to a vote.
Despite the lack of unanimity, it is understood the FIA has decreed that a 70% majority is sufficient to allow the test to take place.
In theory, the FIA could also play the safety card to allow the test to happen, as safety matters do not require unanimity, on the basis that the extra testing is required to guarantee that the tyres Pirelli plans to use in 2020 are safe.
In an added complication the technical regulations specify that the 2020 construction had to be frozen by September 1, a target that Pirelli has missed.
Pirelli's plans for a change in construction reflect the focus on a wider working range that has been requested for next year.
It is understood the planned change relates to the profile of the tyre rather than the tread depth that was a bone of contention earlier this year.
The late notice and the timing of the test between the flyaway races in Russia and Japan means that only the top teams with the biggest resources will be able to do it.
Mercedes is believed to have indicated that it is willing to take part.
- Pirelli's race against time
- The spat forcing F1 to break its own rules
Some teams are concerned that whoever does the October test could potentially gain an advantage by trying the new construction - even in blind conditions - so late in the design process of the 2020 cars.
A big team would potentially have just enough time to make any necessary changes to its suspension design afterwards.
Other teams have agreed that the test can take place for the good of F1, even if they cannot provide a car and take part, as long as it is conducted on a fair basis.
"My view is that we have to be supportive with Pirelli," Alfa Romeo boss Fred Vasseur told Autosport.
"People are always complaining about tyres, and if we want to improve the situation, we have to be supportive of them.
"The FIA asked us the question, and I gave my permission."