McLaren, Alpine and Alfa Romeo are hitting back at the notion that Red Bull and other teams directly benefitted from the aerodynamic rule changes for 2021.
The argument is that Formula 1 and the FIA implemented the changes to disproportionately hurt the most dominant team with the lower 'rake' concept - Mercedes.
"It is clear that the new rules have hit teams like us harder," Aston Martin team boss Otmar Szafnauer is quoted by Auto Motor und Sport.
But McLaren's technical boss James Key says it is too simplistic to say that the 'high rake' teams - led notably by Red Bull - got a free kick with the new rules.
"If the rake angle has any influence, it's only a small one," he said.
"We all started our development for 2021 with cars that were a second slower than last year. What matters most is how you developed from there."
Alpine's Marcin Budkowski agrees: "We are talking about complex air currents and the way they interact with the other components. That is why that (rake) theory is too simple."
Red Bull's Dr Helmut Marko adds: "I think it's about the overall package. You also have to factor in the tyres."
Finally, Alfa Romeo technical boss Jan Monchaux said: "To give a really clear answer, you would need to put Mercedes and Red Bull in a parallel universe.
"I could imagine that a car reacts differently with more or less rake, but in the end I don't think it's about half a second."