McLaren boss Zak Brown says the coronavirus crisis could threaten the very existence of several teams if the sport's current situation is not dealt with "aggressively" by Formula 1.
A disrupted 2020 season that has yet to get underway and the prospect of teams' revenues dropping off a cliff has put F1 "in a very fragile state" according to Brown.
The McLaren chief will be meeting on Monday with his fellow team bosses to discuss the future and potential cost-saving measures, including a lowering of next years' mandatory $175m budget cap.
"This is potentially devastating to teams, and if [it is devastating] to enough teams - which doesn't have to mean more than two - then very threatening to F1 as a whole," Brown told the BBC.
"Could I see - through what is going on right now in the world if we don't tackle this situation head on very aggressively - two teams disappearing? Yeah. In fact, I could see four teams disappearing if this isn't handled the right way.
"And then, given how long it takes to ramp up an F1 team, and given the economic and health crisis we are in right now, to think there would be people lined up to take over those teams like there has historically been... I don't think the timing could be worse from that standpoint.
"So I think F1 is in a very fragile state at the moment."
After the onslaught of the COVID-19 pandemic led to the cancellation or postponement of the opening races of the 2020 season, Formula 1 sealed a series of cost-cutting decisions to help teams mitigate the financial impact of the crisis.
Next year's important regulation overhaul has been delayed until 2022 while teams will extend the use of their 2020 designs into next season.
Brown insists all the sport's teams have agreed to lower the budget cap to $150m for 2021, but the American believes another cutback is necessary.
"You have everyone at $150m, and the strong majority - including one of the big teams - willing to come substantially under $150m," he said.
"If we don't make an aggressive enough budget cap and some people feel they have to top up this year and have no chance of getting it back, then they ask themselves: Why are they in it?
"I don't think anyone competes in F1 just to make up the numbers."
Brown feels that a $100m threshold would significantly help the sport's smaller teams survive the current storm, but a $125m limit could be a more realistic target.
But there are also those who reason that another reduction of the cap would do nothing to help the smaller outfits as their budgets are already well below the $150m ceiling.
While he'll no doubt have the support of the majority of F1's midfield contenders, the McLaren boss is expecting a heated debate on Monday among his peers,
"A couple of the teams are putting their sporting interests well ahead of the greater good and missing the point that they are really running the risk of jeopardising the sport - and then we all lose," Brown said.
"There is a divide. Not a 50-50 divide. I would say it's more 80-20. The reality is you can survive with 80% (of the teams), but you can't survive with 20."
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