Porsche had been expected to join forces with Red Bull from 2026, when new engine regulations are to come into force.
The initial idea was that Porsche would take a 50% shareholding in the Milton Keynes-based operation and would help with the development of the all-new engine that Red Bull is already working on through its powertrains division.
However, it has since emerged that, as Red Bull and Porsche worked through the detail of their plans to work together, hurdles popped up in terms of what both parties were willing to accept.
From Red Bull's perspective, it questioned whether or not it wanted to sacrifice the independence and speed-of-response abilities that had proved a mainstay of its success in F1 to get involved with a large corporate entity.
Red Bull has since made clear that if the Porsche plan is to go ahead then it would have to be entirely on its terms, which has made a shareholding partnership now appear to be off.
The only option that appears to still be open is for Porsche to get involved with Red Bull's powertrains division, although the German car manufacturer had been clear from the off it did not just want to be an engine supplier.
The uncertainty over Porsche's entry means F1's hopes of attracting two new manufacturers for 2026 – with Audi having already confirmed its plan – may be scuppered for now.
However, Domenicali says that there are other car makers sitting on the sidelines waiting for the right opportunity who have kept a deliberately low profile.
Speaking about the Porsche situation ahead of the Italian Grand Prix, Domenicali said: "I can only say that Porsche is an integral part of the group that has discussed and continues to discuss the rules behind the new power unit that will come into force in 2026.
"We have all read comments from Porsche and Red Bull, and they will be them to decide what to do.
"But I believe that we as F1 are currently a very inclusive platform. There are also other manufacturers sitting at the table of the engineers who prefer not to come out into the open."
Domenicali reckoned that F1's 2026 regulations were super attractive to manufacturers and that the sport was robust enough to survive the ebb and flow of car makers who came in and then left.
"For our part, we are not afraid," he said. "In the last Concorde Agreement, we asked only one year's notice to teams or manufacturers who intend to abandon Formula 1, in the past the rules were much stricter.
"This change was included because we feel strong and robust enough to move forward anyway, and there are very good backup plans.
"Today, as never in the past, we have a mix of teams, manufacturers and engine suppliers of the highest level. If something changes we know what to do."
