McLaren chief executive Zak Brown has warned Formula One is in a "very fragile state" due to coronavirus.
The escalating Covid-19 situation has brought the sport to a halt, with the first eight races of the season postponed or cancelled.
F1 is committed to eventually getting the 2020 season under way, but McLaren chief Brown has warned about the potentially perilous state of the sport.
"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," he told BBC Sport.
"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."
McLaren became the first F1 team to furlough staff on Wednesday, with remaining employees, including drivers Lando Norris and Carlos Sainz, taking a wage cut.
But the Woking-based team's chief says more changes are required to help the sport through these uncharted waters, including a considerable reduction to the $175million (£143million) budget cap due to come into force in 2021.
Brown told the BBC that all teams have agreed to lower this year's budget to $150m (£122m) but the McLaren boss wants a further drop ahead of a meeting about the state of F1 on Monday.
"You have everyone at $150m, and the strong majority – including one of the big teams – willing to come substantially under $150m," he added.
