Haas boss Gunther Steiner has expressed doubts that everything Formula 1 needs to resolve in order to finalise its 2021 rules package can be sorted at a meeting next week.
On Tuesday the strategy group - made up of F1, the FIA, and the top six teams - will meet in London in order to discuss and vote on ideas.
It will then will then be followed by a meeting of the F1 commission in which all stakeholders take part and vote.
FIA president Jean Todt has indicated that progress has been made on a 2021 solution, and that it will be apparent at the meetings.
But when asked by Autosport, Steiner raised doubt over a quick-fire resolution: "We need clarity, because there is a lot of talk going on.
"I think now Chase [Carey] is ready to present something to us, and let's see what he presents, and go from there.
"I don't know what is in there. We all talk between each other's backs, so I don't know in the end what F1 has come up with."
Steiner said that the teams need the regulations resolved as soon as possible because of the lead time it would need to prepare for 2021.
He added there are "a lot of things" to discuss and raised doubt that all concerns would sorted in next week's meeting.
"We need to get to the point where we know what is going to happen in the future, otherwise we cannot run our business," he said.
"You cannot start to develop if you have no technical regulations.
"For us everything starts at least a year or 18 months early.
"Now we are only 21 months away from that season. So you haven't got a lot of time left.
"I think they realise that, and that's why they've said, 'We need to come out with something'.
"But there are a lot of things, the governance, the budget cap, the technical regulations. If we get it all done in one meeting, good for us.
"Yeah, good luck."
Specific details of F1's 2021 overhaul has been scarce, with the recent gearbox casette tender one of the few examples in the public domain.
When Steiner was asked if teams had heard about some elements of the technical package, he said: "Yeah, we are hearing about it.
"It's not a done deal. Nothing's a done deal. No package.
"Hopefully we get something on March 26."