At least two teams are at risk of collapse as F1's shutdown period for the coronavirus pandemic continues.

That is the view of former F1 driver Ralf Schumacher, who thinks the team he won all six of his grand prix wins with - Williams - is most directly endangered.

When asked by Bild newspaper if he can imagine teams collapsing whilst no races are taking place, he answered: "We are not far from that.

"If the season doesn't start, I don't know how Williams can survive. Or Haas, who as Americans tend to work according to the 'hire and fire' principle.

"So it may well be that in the crisis they say they will leave Formula 1. By the way, I don't just see problems for the small teams," the German added.

Schumacher, 44, said one solution promoted by Red Bull's Christian Horner and Ferrari's Mattia Binotto - legalising 'customer cars' - could work.

"A brilliant idea," he said.

"A team like Williams would be a lot further ahead if they just bought a Red Bull instead of trying to build their own car. It would also cost them less money."

But Schumacher said the bigger teams, and even reigning world champions Mercedes, may also be in trouble.

"I believe there is a possibility that they could leave Formula 1 due to the crisis at the end of the year," he said.

"We had that with BMW over ten years ago. The possibility is always there although I think that due to Mercedes' successes of recent years, I don't think getting out of F1 will be the first step for them."

Schumacher said he is more interested in the recent moves made by Toto Wolff, who has bought into Aston Martin and will not attend every race as Mercedes team boss in 2020.

"I find the situation around him interesting," he said. "Let's see if he gets back to the pitwall at all after the Aston Martin investment.

"If Mercedes breaks apart due to internal problems, I'm curious to see what will happen to their performance."