McLaren boss Zak Brown has pointed an accusatory finger at "a couple of teams" whose stance on the 2021 budget cap issue risks pushing smaller teams out of the sport.
Teams have agreed to reduce next year's spending limit from $175m to $150m in order to help mitigate the costly impact of the coronavirus crisis on F1.
But while the smaller outfits are pushing for a further reduction of next season's budget cap to $125m or even $100m, Ferrari and Red Bull are currently refusing to budge on the $150m threshold while Mercedes is remaining flexible on the issue.
"Without 10 teams or at least nine teams, you don’t really have F1," Brown told Sky Sports News on Wednesday.
"A couple of teams need to be very careful, because I think they are playing with fire, so to speak.
"It takes a full grid to have a sport, so if they continue to have the sport unsustainable, and a couple of teams lose interest, or financially are not able to participate any more, they are going to be racing against themselves. And that’s not going to work."
Brown refused to specifically name the two front-running outfits which he believes are holding up the changes, but the hints clearly point to Ferrari and Red Bull.
"We’re talking about a couple of teams," added the McLaren Racing chief executive.
"Daimler I think is doing an excellent job, recognising the situation that we’re in. So you can deduct who the other teams are.
"It’s a huge marketing platform for those two teams, so I understand why they want to keep the fiscal balance where it is now.
“But in sport you kind of want to think that everyone can fight fairly and may the best team win. I think they need to have confidence. It’s like a heavyweight who only wants to fight middleweights.
"These are great teams, they should be prepared to fight everyone on more equal terms, and I think that’s what fans want in sport."
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