Dr Helmut Marko has admitted he cannot get enough support to force Pirelli to change its controversial tyres.
The Red Bull official has now played down his earlier comments, in which he hinted Pirelli designed its 2019 tyres especially for Mercedes.
"It cannot be proved that Mercedes got the tyre specification earlier than the others," he told Speed Week. "That's why I would never say that in public.
"It was also said that Mr Gasly would be replaced by Hulkenberg, so God knows what else is said."
But Marko sticks by his earlier claim that Mercedes is the "only team" in pitlane that can get the current Pirellis to work in all conditions.
Nonetheless, he says he cannot get the necessary 7 out of the 10 teams to ask Pirelli for a change.
"Yes, that's how it looks right now," said Marko.
"The satellite teams of Mercedes cannot say anything of course. And strangely enough, McLaren is of the opinion that the tyre does not hurt them.
"So we do not have the required seven teams all together."
Pirelli's F1 boss Mario Isola called Marko's comments "pretty disappointing".
"We provide every team with all the data at the same time," he told Bild newspaper.
Marko also hinted recently that Mercedes may be getting preferential treatment because of a road car alliance with Pirelli. "Unfortunately, our drink cans are not delivered with tyres," he said.
Isola responded: "If a Mercedes is equipped with our tyres, that's no surprise for me. It's our job to sell high-quality tyres for high-quality cars.
"That such suspicions are raised is not good. Sports etiquette is our top priority," he said.
